The Scientific Method is a method of research in which a problem is identified, relevant data are gathered, a hypothesis is formulated from these date, and the hypothesis is empirically rested.
The Scientific Method was used even in ancient times, but it was first documented by England's Sir Francis Bacon (15-61-1626) who set up inductive methods for scientific inquiry.
Scientific method is often spelled out in a simplistic stepwise fashion in textbooks as if it were some sort of recipe or set of instructions that scientists follow. It’s somewhat mythical, not something a working scientist necessarily thinks of and consciously follows step by step. But textbook authors have very limited space and must simplify.
Briefly, scientific method is not a set of instructions for research, but a habit of thought and investigation by which we gain the most reliable and objective information on how the world works—from the world of subatomic particles to the world of galaxies and beyond.
A scientist is, above all, an endlessly curious and highly disciplined person. A scientist has a question about nature. He or she conceives of a possible answer to it framed in the context of what we already know about the subject. That possible answer is called a hypothesis.
A hypothesis is useless and not really scientific at all unless there’s some conceivable way of empirically testing it—i.e., by direct observation. (Stephen Hawking even went so far as to say the string theory of particle physics isn’t really science at all, because there’s no conceivable way of putting it to an empirical test.) So a scientist’s next step is to formulate a way of observationally testing his or her hypothesis.
The test might be simple qualitative observation (not manipulating nature but just observing it with a trained and careful eye—as in much field research in animal behavior and paleontology), or it might be by experimentation (manipulating some variables to see what effect that produces on a system, as medical research, most laboratory science, and some field science).
The test should generate information—data, usually in numerical form. Next, one must ask whether those data really mean anything. Do they truly show an effect of your manipulated (independent) variables on the behavior of a system (dependent variables). This calls for tests of statistical significance—mathematical procedures of great variety, depending on the kind of data one is testing (Student’ t-test, analysis of variance, Person’s product-moment correlation coefficient, Tukey’s range test, and many others). These tests are meant to minimize subjective bias in the interpretation of data. The product of such tests is probability statements. Experimental scientists speak in probabilities, not certainties. Scientists will not say, for example, This proves that disease X is caused by virus Y, or that this new drug controls hypertension or produces leukemia remission better than the old one. Rather, they will make such statements as, There’s at least a 99.5% chance that variable X caused the observed change in variable Y. A careful scientist doesn’t assert “My findings prove ___,” but “My findings are consistent with the hypothesis that ___.”
Then, to have truly “done science,” one must make one’s findings available to the scientific community and the public—that is, publish them. Some say, if you don’t publish it, it’s not science. You’ve contributed nothing to the world’s understanding if you don’t publish. Public knowledge is the ultimate goal of science, not just the satisfaction of personal curiosity.
To publish one’s findings, one must first demonstrate that the work was important enough to warrant a share of the limited and expensive space in a recognized scientific journal; then show that one’s hypothesis and methods were sound; then show that the results were meaningful—often, but not always, by demonstration of statistical tests of confidence.
All of this entails surviving a process of peer review, in which an editor or grant agency sends your draft publication out to other experts in your field, whose job is basically to find fault (if there is any) with what you’ve done: to closely scrutinize your logic, assumptions, methods, findings, and tests of significant to see if they can find anything wrong with it, serious enough that you need to revise your paper or the journal editor should outright reject it for publication. The prestigious journals Cell, Science, and Nature reject 97% of all papers that scientists submit for publication, for various reasons including insufficient importance to warrant publication, inappropriateness of subject matter to those journals, unclear hypotheses, fallacious methods, poor analysis of the results, violation of research ethics, or poor writing.
41.6 g Al(NO3)3m Are added to a flask, how many liters of water should be added to create a 0.450 M solution?
To calculate the volume of water needed to create a 0.450 M solution of Al(NO3)3, we need to use the formula:
Molarity = moles of solute / volume of solution in liters
First, we need to determine the number of moles of Al(NO3)3 we have:
moles of Al(NO3)3 = mass / molar mass
molar mass of Al(NO3)3 = 1 x atomic mass of Al + 3 x atomic mass of N + 9 x atomic mass of O = 1 x 26.98 + 3 x 14.01 + 9 x 16.00 = 212.99 g/mol
moles of Al(NO3)3 = 41.6 g / 212.99 g/mol = 0.195 mol
Next, we can rearrange the formula above to solve for the volume of solution:
volume of solution = moles of solute / molarity
volume of solution = 0.195 mol / 0.450 M = 0.433 L
Therefore, we need to add 0.433 L (or 433 mL) of water to 41.6 g of Al(NO3)3 to create a 0.450 M solution.
determine the mass in grams of 0.75 moles of cr2(so4)3
Answer: The mass in grams is 290g.
Explanation: In order to find the mass you need to multiply the number of moles given by the molar mass of the compound.
You find the molar mass by adding all the atomic masses of each atom in the compound.
Since 0.75 has 2 significant figures, your final answer also needs to have 2 sig figs.
26. The normal boiling point of argon is 21.9K and its latent heat of vaporization is 1.57kJ/mol. Calculate it's boiling point at 1.2 atm.
Using the Clausius-Clapeyron equation, we can see that the new boling point is 34.6 K.
How to find the new boiling point?To calculate the boiling point of argon at 1.2 atm, we can use the Clausius-Clapeyron equation, which relates the boiling point of a substance at one pressure to its boiling point at another pressure, along with the latent heat of vaporization.
The Clausius-Clapeyron equation is given as:
ln(P1/P2) = ΔHvap/R * (1/T1 - 1/T2)
where:
P1 and P2 are the initial and final pressures, respectively,ΔHvap is the latent heat of vaporization,R is the ideal gas constant (8.314 J/(mol*K)),T1 and T2 are the initial and final temperatures in Kelvin, respectively.Given:
P1 = 1 atm (normal pressure)P2 = 1.2 atm (given pressure)T1 = 21.9 K (normal boiling point of argon)ΔHvap = 1.57 kJ/mol = 1.57 * 10^3 J/mol (latent heat of vaporization)We can rearrange the Clausius-Clapeyron equation to solve for T2 (the boiling point at 1.2 atm):
ln(P1/P2) = ΔHvap/R * (1/T1 - 1/T2)
Rearranging further:
1/T2 = (ln(P1/P2) * R) / ΔHvap + 1/T1
Plugging in the given values:
1/T2 = (ln(1 atm / 1.2 atm) * (8.314 J/(mol*K))) / (1.57 * 10^3 J/mol) + 1/21.9 K
Simplifying:
1/T2 = -0.0624 + 0.0456 + 0.0457
1/T2 = 0.0289
T2 = 1 / 0.0289
T2 = 34.6 K
That is the new one.
Learn more about the boiling point at:
https://brainly.com/question/40140
#SPJ1
What is the molarity of a solution containing 65 grams of KCl if there is
8.3 L of solution?
Answer: The molarity of the solution is 0.11 M.
Explanation: You first need to convert 65g of KCl to moles of KCl. When you do that you will get 0.871898055 moles of KCl, round anykind of answers you get at the end.
The second step is to use the molarity formula to find the molarity of the solution. Molarity = moles/liters
Molarity = 0.871898055 moles of KCl / 8.3 Liters of solution
M = 0.11
Make sure that your answer always has the correct number of significant figures. In the question both numbers given to you have 2 sig figs, therefore your final answer also needs to have 2 sig figs.
ACTIVITY: SOLUTION CONCENTRATION VS. CONDUCTIVITY
Here is your goal for this lesson:
Graph experimental data and interpret results for peer review
A chemistry student carried out an experiment with a conducting apparatus (ammeter) similar to the one below. This ammeter measures in milliamperes (mA). The following data was taken.
Solution Reading
0.1 M H2SO4 150 mA
0.1 M Ba(OH)2 150 mA
To 30 mL of the Ba(OH)2 solution, 10 mL portions of H2SO4 were added until a total of
50 mL of H2SO4 were used. The following results were recorded.
DATA TABLE
Total H2SO4 Added Meter Reading Observations
0 mL 150 mA Ba(OH)2 and H2SO4 clear, colorless
10 mL 65 mA milky white precipitate forms
20 mL 31 mA more precipitate forms
30 mL 0 mA precipitate heavy and settles
40 mL 29 mA no added precipitate seen to form
50 mL 62 mA no change seen
Questions
1. Did you plot the data? yes or no
2. Did you label your graph axes? no or yes
3. Did you give your graph a title? no or yes
4. Does the Ba(OH)2 solution contain ions? yes or no
5. Does the H2SO4 solution contain ions? yes or no
6. Explain the data.
Is there any evidence that a reaction has occurred?
7. Does the conductivity increase or decrease?
8. Does the number of ions in solution increase, decrease, or remain constant?
9. What is the indicator of the number of ions in solution?
10. How does this evidence indicate that the reaction has occurred between ions?
11. The Ba(OH)2 dissociates as Ba+2 + 2 OH-. H2SO4 dissociates as 2 H+ + SO4-2.Write a balanced equation for this reaction.
12. When the conductivity is at a minimum, what must be true about the amount of Ba(OH)2?
13. Why does it not conduct at this low point?
14. Why does it conduct more before and after this minimum point?
The data obtained from the experiment shows a clear indication that a reaction has occurred between the H₂SO₄ and Ba(OH)₂ solutions. As the H₂SO₄ solution is added to the Ba(OH)₂ solution, the ammeter reading decreases indicating a decrease in conductivity.
The decrease in conductivity is due to the formation of an insoluble white precipitate, BaSO₄, as seen in observations. When no more H₂SO₄ is added, the ammeter reading stabilizes, indicating that the reaction has reached completion, as seen in observations e and f.
The formation of BaSO₄ precipitate indicates that the sulfate ion, SO₄²⁻, from H₂SO₄, has reacted with the barium ion, Ba²⁺, from Ba(OH)₂, forming an insoluble salt. This is a typical example of a precipitation reaction, where two aqueous solutions are mixed, resulting in the formation of an insoluble solid product.
To learn more about ammeter follow the link:
https://brainly.com/question/29513951
#SPJ1
The question is inappropriate; The complete question is:
A chemistry student carried out an experiment with a conducting apparatus (ammeter) similar to the one below. This ammeter measures in milliamperes (mA). To 30 mL of the Ba(OH)2 solution, 10 mL portions of H2SO4 were added until a total of 50 mL of H2SO4 were used.
Explain the data. Is there any evidence that a reaction has occurred? How does this evidence indicate that the reaction has occurred between ions?
Can you help me solve number 4?
The pressure of the gas in the flask, given that the temperature is reduced to -15 is 0.38 mmHg
How do i determine the pressure of the gas?From the question given above, the following data were obtained:
Initial pressure (P₁) = 338 mmHgInitial temperature (T₁) = 72 °C = 72 + 273 = 345 KInitial volume (V₁) = 0.225 LNew volume (V₂) = 150 LNew temperature (T₂) = -15 °C = -15 + 273 = 258 KNew pressure (P₂) = ?The new pressure of the gas can be obtained by using the combined gas equation as shown below:
P₁V₁ / T₁ = P₂V₂ / T₂
(0.225 × 338) / 345 = (P₂ × 150) / 258
Cross multiply
345 × 150 × P₂ = 0.225 × 338 × 258
Divide both sides by (345 × 150)
P₂ = (0.225 × 338 × 258) / (345 × 150)
P₂ = 0.38 mmHg
Thus, we can conclude the pressure of the gas is 0.38 mmHg
Learn more about pressure:
https://brainly.com/question/15343985
#SPJ1
Using this balanced equation:
NaHCO3 + CH3COOH H2O + CO2 + NaC2H3O2
In an experiment , the following mass measured 3.0 grams, 5.5 grams and 7.0 grams of
sodium bicarbonate is mixed with 0.5 mol of acetic acid (vinegar) to form carbon dioxide as
a product formed
The stoichiometric ratio of NaHCO₃ to CH₃COOH, which is determined by the balancing equation, is 1:1, meaning that 1 mole of NaHCO₃ reacts with 1 mole of CH₃COOH.
What is the balanced equation between vinegar's acetic acid CH₃COOH and sodium bicarbonate NaHCO₃?Acetic acid (CH₃COOH), a component of vinegar, interacts with sodium bicarbonate (NaHCO₃) in baking soda to produce water, carbon dioxide gas, and sodium acetate.
When NaHCO₃ and HC₂H₃O₂ are joined in a closed system, what do you suppose would happen?CO₂(g) + H₂O(l) + NaC₂H₃O₂ = NaHCO₃(aq) + HC₂H₃O₂(aq) when yellow bubbles appear, an acidic gas H₂CO₃ has generated as a result of the reaction between CO₂ and water. The salt in the solution (NaC₂H₃O₂) is basic since the solution is red in colour.
To know more about stoichiometric visit:-
https://brainly.com/question/29856106
#SPJ1
1, The activation energy of the reaction is 71 KJ/Mol how many time is greater the rate constant for the reaction at temperature of 170°c and 150°c.
Answer:
cual es el propósito de este experimento
Question 7 (Essay Worth 5 points) (03.02 MC) Is this a scientific model? Use complete sentences to explain why or why not. !!PLS HELP :( !!!
The image is not a scientific model
Is this a scientific model?A scientific model is a condensed representation of a real-world occurrence that helps scientists understand and justify it. In order to make predictions or test hypotheses, scientists utilize models. They could be intellectual, mathematical, or physical.
On the other hand, a NASA image is a visual representation of a real-world item, situation, or phenomenon that has been captured by a spacecraft or telescope. Images from NASA are accurate depictions, not simplified renditions, of what was observed in space.
Learn more about scientific model:https://brainly.com/question/18893139
#SPJ1
2) The lowest atmospheric pressure at sea level in the Western Hemisphere was recorded in 2015 during
hurricane Patricia: a pressure of 656 torr. Show unit cancelation in work.
a) What is this pressure in kilopascals?
To convert torr to kilopascals, we can use the following conversion factors:
1 torr = 1/760 atm
1 atm = 101.325 kPa
So, we can write: 656 torr × (1/760 atm) × (101.325 kPa/atm) = 87.0 kPa
Therefore, the atmospheric pressure during hurricane Patricia was 87.0 kPa.
Certainly!
In this exercise, converting a pressure value from torr to kilopascals (kPa) is required. Torr is a common unit of pressure used in physics and chemistry, while kPa is a common unit of pressure used in engineering and other disciplines.
We may utilise a conversion factor that connects torr to kPa to carry out the conversion. We must employ the following conversion factor:
0.133322 kPa per torr
As a result, 0.133322 kPa is equal to 1 torr. A pressure value in torr may be converted to a pressure value in kPa by multiplying the torr value by the conversion factor. This enables us to eliminate the torr units and obtain a value in kPa.
Learn more about kilopascals at:
https://brainly.com/question/24877263
#SPJ1
A 2135 ml sample of N₂ has a pressure of 95.4KPa at 135°C. What is the volume of the sample if temperature is
increased to 223°C and the pressure is kept constant?
B. 2595 ml
A. 913 ml
C. .3484 ml
D. 900 ml
Answer:
The correct answer is C: 3484 ml
Baliz reply asap, help indeed needed lol
In the SI system of units [International System of Units], the mole is one of seven base units. It is frequently used in chemical calculations. However, a mole of something is just a particular quantity of it. It is not a unit of measure in the way that meters, seconds, and kilograms are. Calculations performed with the number of moles of a substance could also be performed with the number of particles of a substance. Based on this information, do you think that the mole should be considered a base unit in the SI system? Explain why or why not.
Based on the information given, the mole should be considered a base unit in the SI system because it serves as a universally accepted measure of the amount or quantity of substances.
The mole is an amount unit similar to familiar units like pair, dozen, gross, etc. It provides a specific measure of the number of atoms or molecules in a bulk sample of matter.
A mole is defined as the amount of substance containing the same number of atoms, molecules, ions, etc. as the number of atoms in a sample of pure 12C weighing exactly 12 g.
SI units refer to units of measurement that are universally accepted for measuring the properties of quantities of objects.
Learn more about Moles, here:
https://brainly.com/question/31597231
#SPJ1
If an equal quantity of heat is added to equal masses of Copper and Water, estimate the final
temperature difference
The temperature of copper would rise by 263.8°C more than the temperature of water if we added the same amount of heat to equal masses of each substance.
What do you mean by specific heat capacity?Specific heat capacity is the amount of heat energy required to raise the temperature of one unit mass of a substance by one degree Celsius or Kelvin. To estimate the final temperature difference, we can use the specific heat capacity of each substance.
The specific heat capacity of copper is 0.385 J/g°C, while the specific heat capacity of water is 4.184 J/g°C. This means that water requires over ten times as much heat energy as copper to raise its temperature by one degree Celsius.
If we add an equal quantity of heat (in joules) to equal masses of copper and water, we can expect the temperature of copper to rise much more than the temperature of water. In fact, we can calculate the temperature difference using the following formula:
Q = mCΔT
where Q is the amount of heat added, m is the mass of the substance, C is its specific heat capacity, and ΔT is the change in temperature.
If we assume that we add the same amount of heat to equal masses of copper and water (let's say 100 grams each), then we can set up two equations using the specific heat capacities of each substance:
Q = 100 * 0.385 * ΔT (for copper)
Q = 100 * 4.184 * ΔT (for water)
Since Q is the same in both equations (we added the same amount of heat to each substance), we can set the two equations equal to each other and solve for ΔT:
100 * 0.385 * ΔT = 100 * 4.184 * ΔT
0.385 * ΔT = 4.184 * ΔT
3.799 * ΔT = Q (where Q is the amount of heat added)
ΔT = Q / 3.799
So, if we added 1000 joules of heat to 100 grams each of copper and water, we can expect the temperature difference between the two substances to be:
ΔT = 1000 / 3.799 = 263.8°C
This means that the temperature of copper would rise by 263.8°C more than the temperature of water if we added the same amount of heat to equal masses of each substance. However, it's important to note that this is a theoretical estimate, and in reality, there would be some loss of heat to the surroundings, which would affect the final temperature difference.
Learn more about heat here:
https://brainly.com/question/1429452
#SPJ9
What materials formed the solar system?
Answer:
The solar system formed from a cloud of gas and dust, known as the solar nebula, that collapsed under its own gravity about 4.6 billion years ago. As the solar nebula collapsed, it formed a spinning disk of gas and dust, with most of the material concentrated at the center. Over time, the material in the disk began to clump together due to gravity, forming small rocky and icy planetesimals, which collided and merged to form larger bodies. These larger bodies eventually became the planets, moons, asteroids, and other objects that make up the solar system today. The exact composition of the solar nebula and the materials that formed the solar system varied depending on the distance from the Sun and the temperature and pressure conditions in different regions of the nebula. Generally, the inner solar system (including the Sun, Mercury, Venus, Earth, and Mars) is composed mostly of rocky materials, while the outer solar system (including the gas giants Jupiter, Saturn, Uranus, and Neptune, as well as the dwarf planet Pluto) is composed mostly of ices, such as water, ammonia, and methane, as well as gases like hydrogen and helium.
short term answer: dust and gas.
Explanation: learned it in 5th grade science class, bye have a great day !
A compound containing only sulfur and phosphorus is 50.9% S by mass; the molar mass is 252 g/mol. What are the empirical and molecular formulas of the compound?
The compound's empirical formula is [tex]S_2P[/tex]. We must ascertain the molar mass of the empirical formula in order to derive the molecular formula.
What is compound?A substance created when two or more elements are chemically mixed in a specific ratio is referred to be a compound. In general, compounds differ from mixes, which are made up of various ingredients in a random arrangement. Compounds contain things like carbon dioxide ([tex]Co_2[/tex]), table salt ([tex]Nacl[/tex]), and water ([tex]H_2o[/tex]). Chemical reactions can transform compounds into less complex ones.
[tex]S_2P[/tex] has a molar mass of 120 g/mol. The empirical formula must be multiplied by two to obtain the molecular formula, which is [tex]S_4P_2[/tex], because the compound's molar mass is 252 g/mol.
To learn more about compound, visit:
brainly.com/question/29108029
#SPJ1
What would the expected temperature change be (in F) if 0.5 gram sample of water released 0.0501 j of heat energy? The specific heat of liquid water 4.184 j/g
The expected temperature change would be approximately 4.32°F if 0.5-gram sample of water released 0.0501 j of heat energy.
The specific heat of a substance is the amount of heat energy required to raise the temperature of one gram of the substance by one degree Celsius. The expected temperature change can be calculated using the formula:
q = m × c × ΔT
where q is the heat energy released, m is the mass of water, c is the specific heat of water, and ΔT is the change in temperature.
Rearranging the formula to solve for ΔT, we get:
ΔT = q ÷ (m × c)
Substituting the given values, we get:
ΔT = 0.0501 J ÷ (0.5 g × 4.184 J/g°C)
ΔT ≈ 2.4°C or 4.32°F
When a substance undergoes a change in temperature, it either gains or loses heat energy.
To learn more about temperature follow the link:
https://brainly.com/question/15267055
#SPJ1
state and explainvtwo conditions under which the intesity of the brown colour of the equlibrium mixture can be increased
a)condition1
b)condition2
find [N₂ O₄] given K = 0.028, [NO₂] = 0.0.042 M N₂O₄ ← →2 NO₂
The reaction between N2O4 and is at equilibrium at this time.2 Given by K = 0.028 is NO2. The amount of NO2 in the sample is 0.042 M.
K = [NO2] is the equilibrium expression for the reaction.²/[N₂O₄] When K and [NO2] are substituted in the equilibrium expression, we obtain 0.028 = (0.042).²/[N₂O₄]
We get at [N2O4] = 0.028/0.0422 = 0.0075 M after solving for [N2O4].
Learn more about equilibrium at:
https://brainly.com/question/30807709
#SPJ1
How many liter of CO2 gas at STP will contain 2136 molecules?
Answer: 2136 molecules of CO2 at STP will occupy a volume of 8.91 × 10^-24 L
Explanation:
STP (standard temperature and pressure), 1 mole of any gas occupies 22.4 L of volume. Also, 1 mole of any gas contains 6.022 × 10^23 molecules.
1 mole of CO2 contains = 6.022 × 10^23 molecules
Therefore, 2136 molecules of CO2 will be present in a volume of:
= (1 mole CO2 / 6.022 × 10^23 molecules CO2) × (22.4 L / 1 mole CO2) × (2136 molecules CO2 / 1)
= 8.91 × 10^-24 L
what is chemical equitation
Answer:
A chemical equation is the symbolic representation of a chemical reaction in the form of symbols and formulae, wherein the reactant entities are given on the left-hand side and the product entities on the right-hand side.
Explanation:
Good luck!
Answer:
A chemical equation is the symbolic representation of a chemical reaction in the form of symbols and chemical formulas.
What is in a chemical equation?
A chemical equation (see an example below) consists of a list of reactants (the starting substances) on the left-hand side, an arrow symbol, and a list of products (substances formed in the chemical reaction) on the right-hand side.
Hope this helps :)
Pls brainliest...
Question 14(Multiple Choice Worth 3 points)
[FW.03]The amount of dissolved oxygen in water may decrease because of the
decrease in density of water
increase in plants in the water
decrease in temperature of water
O increase in organic matter in the water
The amount of dissolved oxygen in water may decrease because of the decrease in temperature of water. therefore, the correct option is option C.
Remember the adage "like dissolves like." This indicates that for substances to form solutions, their intermolecular forces must be comparable. When a water-soluble solute is added to a solvent, the solute and solvent particles may come into contact.
When a liquid or solid solute is present, the interactions among the solute and solvent particles become so powerful that the individual particles of solute split from one another and enter the solution encircled by solvent molecules. The amount of dissolved oxygen in water may decrease because of the decrease in temperature of water.
Therefore, the correct option is option C.
To know more about dissolution, here:
https://brainly.com/question/23851972
#SPJ1
Reaction 1 : 4 NH 3(g) + 5 O2(g) → 4 NO(g) + 6 H2O(l) ΔG° = −1010 kJ/molrxn
Reaction 2 : 2 NO 2(g) → 2 NO(g) + O2(g) ΔG° = 70 kJ/molrxn
Reaction 3 : 4 NO 2(g) + O2(g) + 2 H2O(l) → 4 HNO 3(aq) ΔG° = −170 kJ/molrxn
Based on the values of ΔG° for the three reactions represented above, what is the value of ΔG° for the reaction
represented below?
4 NH3(g) + 8 O2(g) → 4 HNO 3(aq) + 4 H2O(l)
(A) −1040 kJ/molrxn
(B) −1110 kJ/molrxn
(C) −1250 kJ/molrxn
(D)−1320 kJ/molrxn
* Please explain how you got to the answer you did
Based on the values of ΔG° for the three reactions represented above, the value of ΔG° for the reaction given is −1320 kJ/molrxn. The correct option is D.
To determine the value of ΔG° for the given reaction, we can use Hess's law, which states that the change in enthalpy (ΔH) for a reaction is equal to the sum of the enthalpy changes for a series of reactions that add up to the original reaction.
The same principle applies to Gibbs free energy (ΔG), so we can use the ΔG° values for the three given reactions to calculate the ΔG° for the target reaction.
We can use Reaction 1 and Reaction 2 to obtain the following overall reaction, which is the reverse of Reaction 3:
[tex]4 NH_3(g) + 6 O_2(g) --- > 4 NO(g) + 6 H_2O(l)[/tex] ΔG° = 1010 kJ/molrxn
[tex]2 NO_2(g) + O_2(g) --- > 2 NO(g) + O_2(g)[/tex] ΔG° = -70 kJ/molrxn (reverse of Reaction 2)
Next, we can add the two reactions above to obtain:
[tex]4 NH_3(g) + 8 O_2(g) + 2 NO_2(g) --- > 4 NO(g) + 4 HNO_3(aq)[/tex] ΔG° = 940 kJ/molrxn
Finally, we can use Reaction 3 to obtain the target reaction by adding 4 HNO3(aq) and subtracting 2 H2O(l):
[tex]4 NH_3(g) + 8 O_2(g) --- > 4 HNO_3(aq) + 4 H_2O(l)[/tex] ΔG° = -170 kJ/molrxn
Therefore, the answer is (D) −1320 kJ/molrxn.
For more details regarding chemical reaction, visit:
https://brainly.com/question/29039149
#SPJ1
1. What will be the final concentration of the solution indicated that will result from the
following dilutions?
a. 14.0 ml of a 4.2 M Na2CO3 solution is diluted to 86.0 ml.
Taking into account the definition of dilution, the final concentration of the solution is 0.68 M.
Definition of dilutionDilution is the process of reducing the concentration of solute in solution, which is accomplished by simply adding more solvent to the solution.
In a dilution the amount of solute does not change, but as more solvent is added, the concentration of the solute decreases, and the volume of the solution increases.
A dilution is mathematically expressed as:
Ci×Vi = Cf×Vf
where
Ci: initial concentrationVi: initial volumeCf: final concentrationVf: final volumeFinal concentrationIn this case, you know:
Ci: 4.2 MVi: 14 mLCf: ?Vf: 86 mLReplacing in the definition of dilution:
4.2 M× 14 mL= Cf× 86 mL
Solving:
(4.2 M× 14 mL)÷ 86 mL= Cf
0.68 M= Cf
In summary, the final concentration is 0.68 M.
Learn more about dilution:
brainly.com/question/6692004
#SPJ1
What would you expect the effect of pH to have on the surface charge of aqueous solutions of gold nanocrystals capped with alkanethiols bearing either terminal carboxylic acid or amine groups? What would you expect to happen on mixing these two kinds of nanocrystals at different pH?
Depending on the pH of the solution, the surface charge of each nanocrystal, and the mixing of these two types of nanocrystals, complicated interactions may occur.
What feature of nanoparticles is most significant?Friction is the most significant characteristic of nano metals. One of the many characteristics that make nanomaterials special is their small size. Nanomaterials can have a size up to a thousand times smaller than a human hair. The ratio of a nanoparticle's surface area to volume is very high.
What occurs when different pH levels of gold nanocrystals with carboxylic acid- and amine-capped surfaces are combined?Because of their distinct surface charges, these two different kinds of nanocrystals may exhibit electrostatic attraction or repulsion when combined in different pH environments. Positively charged nanocrystals with carboxylic acid caps may draw negatively charged ones with amine caps when the pH is low. The carboxylic acid-capped nanocrystals have a greater negatively charged surface charge when the pH rises, which may cause them to reject one another. The amine-capped nanocrystals, on the other hand, have a higher positive change in surface charge, which could cause them to attract.
To know more about the pH value visit:
https://brainly.com/question/26856926
#SPJ1
An atom has 21 electrons, 17 protons and 18 neutrons. What is the total charge of the atom?
Explanation:
Only protons and electrons contribute to the charge of an atom ...NEUTRons are NEUTRal...
Protons are + charge
Electrons are - charge
21 negative charges added to 17 positive charges results in
- 4 charge
A researcher wants to determine the success rate of a driver’s education program conducted in high schools in a particular state. Which method would assure random selection of a sample from the population? The researcher should select one high school in the state and survey all of the students in that school who are enrolled in the training program. The researcher should randomly select one high school in the state and survey a random batch of students who are enrolled in the training program. The researcher should randomly select a city in the state and survey all students in that city who are enrolled in the training program. The researcher should randomly select students from among all the students in the state who are enrolled in the training program.
The method that would assure random selection of a sample from the population is:
The researcher should randomly select students from among all the students in the state who are enrolled in the training program.
This method ensures that all students enrolled in the driver's education program in the state have an equal chance of being selected for the study. Random selection helps to eliminate bias and increases the likelihood that the sample is representative of the entire population.
The other options listed would not assure random selection of a sample from the population.
Selecting one high school or one city could introduce bias into the sample, as the success rate of the driver's education program may vary between different schools or cities.
Thus, selecting a random batch of students from one high school could also introduce bias into the sample, as the students selected may not be representative of all students enrolled in the driver's education program in the state.
For more details regarding Random selection, visit:
https://brainly.com/question/10678373
#SPJ1
Sharna then mixed cabbage-water with lemon juice. Lemon juice is acidic. What colour was the mixture?
What is the cell potential for the reaction
Mg(s)+Fe^2+(aq)→Mg^2+(aq)+Fe(s)
at 89 degrees celsius when [Fe2+] = 2.80 M
and [Mg2+] = 0.110 M
solve and show steps. I have tried 2.86 and 6.2653 and both were not correct
show answer in 3 sig figs
The cell potential for the reaction Mg(s)+Fe2+(aq)Mg2+(aq)+Fe(s) is 2.87 V at 89 degrees Celsius.
The Nernst equation can be used to compute this: Where E° cell is the standard cell potential, R is the gas constant, T is the temperature in Kelvin, n is the number of electrons transported, F is the Faraday constant, and Q is the reaction quotient, E cell is defined as E° cell - (RT/nF)lnQ.
E° cell = -2.37 V, R = 8.314 J/K-mol, T = 362 K, n = 2, F = 96485 C/mol, and Q = [Mg2+]/[Fe2+] = 0.110/2.80 = 0.039 in this instance. The Nernst equation using these values as input produces the result E cell = -2.37 - (8.314*362/2*96485)ln(0.039) = 2.87 V.
Learn more about E° cell at:
https://brainly.com/question/2491198
#SPJ1
A balloon has a volume of 145 mL at room temperature (25°C = 298°K). Alyssa decides to place the balloon in the freezer to see what happens. After being in the freezer for an hour, the balloon has a new volume of 35mL. What is the temperature inside the freezer?
The temperature inside the freezer is approximately -164°C.
To solve this problem, we can use the combined gas law equation:
[tex](P1V1)/T1 = (P2V2)/T2[/tex]
where P is the pressure, V is the volume, and T is the temperature of the gas.
We know that the initial volume of the balloon is 145 mL and the final volume is 35 mL. We also know that the initial temperature is 25°C or 298 K, and we need to find the final temperature.
Assuming the pressure of the gas remains constant, we can rearrange the combined gas law equation to solve for the final temperature:
[tex]T2 = (P2V2/T1)(P1/V1)[/tex]
Plugging in the values we know, we get:
[tex]T2 = (1 atm * 35 mL/298 K)(1 atm/145 mL) = 0.0808 atm/mL[/tex]
Multiplying both sides by 298 K and dividing by 0.0808 atm/mL, we get:
T2 = 109.15 K or approximately -164°C
Therefore, the temperature inside the freezer is approximately -164°C.
Learn more about combined gas law, here:
https://brainly.com/question/30458409
#SPJ1
what is the force that exists between atoms that are in different molecules
Intermolecular force connects atoms in different molecules. Intermolecular forces determine physical qualities including boiling temperature, melting point, viscosity, and surface tension.
London dispersion, dipole-dipole, and hydrogen bonding are intermolecular forces. London dispersion forces, caused by electron movement-induced dipoles, are the smallest intermolecular interactions between all atoms and molecules.
Polar molecules have greater dipole-dipole interactions than London dispersion forces. Hydrogen bonding is a specific dipole-dipole interaction between a hydrogen atom bound to an electronegative atom (N, O, or F) in one molecule and an electronegative atom in another molecule.
Learn more about intermolecular forces, here:
https://brainly.com/question/9007693
#SPJ1