Explanation:
i.Periodic table:It is a chart or table of the elements arranged into columns and rows according to their physical and chemical properties.
ii.Period on the periodic table:The horizontal rows of elements
iii.Column on the periodic table:The vertical representation of elements
If 6.75 g of NaOH are dissolved in 50.00 g of water and the temperature increases
from 20.5°C to 47.8 °C.
a. Is this an example of an endothermic or exothermic reaction?
b. What is the q for the reaction? (Remember since the NaOH dissolves in water add the
masses to get the m)
C. How many moles of NaOH are dissolved?
d. What is the AH for the reaction?
Answer: THE STANDARD HEAT OF SOLUTION OF SODIUM HYDROXIDE IN WATER IS -7.68 KJ PER MOLE.
Describe the three values in a learner-centred curriculum that a teacher can use
to create a pedagogy of care in the classroom.
Answer:
to talk in a way that the class can all understand . help them in thing they are falling . and have a good relashaship.
Explanation:
What is the Same about carbohydrates, proteins , and fats ?
Answer:
The main similarity between carbohydrates, proteins and fats is that they are all used for energy.
Explanation:
I hope this helps, have a blessed day.
When a certain nuclide undergoes alpha emission, astatine-217 is produced. What is the identity of the nuclide that underwent decay?
a. actinium-219
b. francium-217
c. francium-221
d. astatine-221
e. actinium-221
Please explain the answer
Answer:
C: francium-221
Explanation:
First of all to get a broader perspective, every isotope of francium usually undergoes decay to form astatine, radium, or radon.
Now, Francium-223 and francium-221 are it's only isotopes that occur in nature.
However, francium-221 is the one that undergoes alpha decay to produce astatine-217.
A generator makes electricity from _____.
chemical reactions
kinetic energy
heat
friction
If there are 1.55 x 1024 molecules of hydrogen peroxide (H2O2), what is the mass of the
sample?
Answer:
87.54 g of H₂O₂
Explanation:
From the question given above, the following data were obtained:
Number of molecules = 1.55×10²⁴ molecules
Mass of H₂O₂ =.?
From Avogadro's hypothesis,
6.02×10²³ molecules = 1 mole of H₂O₂
Next, we shall determine the mass of 1 mole of H₂O₂. This can be obtained as follow:
1 mole of H₂O₂ = (2×1) + (2×16)
= 2 + 32
= 34 g
Thus,
6.02×10²³ molecules = 34 g of H₂O₂
Finally, we shall determine mass of H₂O₂ that contains 1.55×10²⁴ molecules. This can be obtained as follow:
6.02×10²³ molecules = 34 g of H₂O₂
Therefore,
1.55×10²⁴ molecules
= (1.55×10²⁴ × 34)/6.02×10²³
1.55×10²⁴ molecules = 87.54 g of H₂O₂
Thus, 87.54 g of H₂O₂ contains 1.55×10²⁴ molecules.
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Which of the following things is not made of wither fermentation?
Cheese
Yogurt
Bread
Peanut butter
Chocolate
How does an electric field change and influence its surroundings?
Answer:
The electric force acts over the distance separating the two objects. ... The space surrounding a charged object is affected by the presence of the charge; an electric field is established in that space. A charged object creates an electric field - an alteration of the space or field in the region that surrounds it.
Explanation:
The shadow of a groundhog ( or anything else ) is determined what?
The size, length, and height of the figure are the main factors which determine the shadow of a organism.
The size, length, and height of the figure are the main factors which determine the shadow of a organism.
What is a shadow?A shadow is a dark area where light from a light source is blocked by an opaque object. It occupies all of the three-dimensional volume behind an object with light in front of it. The cross section of a shadow is a two-dimensional silhouette, or a reverse projection of the object blocking the light.
A point source of light casts only a simple shadow, called an "umbra". For a non-point or "extended" source of light, the shadow is divided into the umbra, penumbra, and antumbra. The wider the light source, the more blurred the shadow becomes. If two penumbras overlap, the shadows appear to attract and merge. This is known as the shadow blister effect.
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Which of the following contains the highest number of electrons?
OA) hydroxide ion
OB) oxonium ion
C) ammonium ion
OD) oxide ion
O E) all of them contains the same number of electrons
how many moles of an NH3 can be produced from 2.82 moles of nitrogen in the following reaction:
Seeds, flowers, and fruits work together to help a flowering plant reproduce.
Each of these structures is made up of different kinds of tissues specialized
to perform a specific function. What level of body organization does this
group (plants, seeds, and flowers) represent?
A. Organ
B. Cell
C. Cell system
D. Body system. not B
Answer:
I think the body system
Explanation:
Answer:body system
Explanation:
Introduction: Reaction rates are also influenced by surface area and concentration. The surface area of a solid is a measure of how much of the solid is exposed to other substances. The concentration of a substance is a measure of how many molecules of that substance are present in a given volume. Question: How do surface area and concentration affect reaction rates
Answer:
See explanation
Explanation:
Surface area has to do with the number of solid particles that are exposed at a given time and is capable of colliding with other reactant particles. When more surface area is exposed for reaction, then it means that more particles are likely to collide with each other leading to faster chemical reaction rates. When few particles are exposed for reaction (low surface area) then less collisions occur and the rate of reaction is decreased.
Similarly, concentration refers to the amount of substance present. The greater the amount of substance present, the greater the likelihood of collision between particles and the greater the rate of reaction and vice versa.
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Answer:
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Explanation:
200 IQ intellectual right here ^^
Pls help ASAP it’s timing meeee!!!!!
Potassium nitrate, KNO3 , has a molar mass of 101.1 g/mol. In a constant-pressure calorimeter, 13.3 g of KNO3 is dissolved in 213 g of water at 23.00 °C . KNO3(s)−→−−H2OK+(aq)+NO−3(aq) The temperature of the resulting solution decreases to 19.60 °X . Assume that the resulting solution has the same specific heat as water, 4.184 J/(g·°C) , and that there is negligible heat loss to the surroundings. How much heat was released by the solution
Answer:
[tex]Q_{sln}=-3219.25 J[/tex]
Explanation:
Hello there!
In this case, for this calorimetry problem, it is possible for us to infer that the heat of the reaction of dissolution of KNO3 is absorbed by the solution composed by the former and water so that we can write:
[tex]Q_{rxn}=-Q_{sln}[/tex]
Thus, given the mass, specific heat and temperature of the solution, we plug in the data to obtain the heat absorbed, by the reaction:
[tex]Q_{rxn}=-m_{sln}C_{sln}\Delta T _{sln}\\\\Q_{rxn}=-(13.3+213)g(4.184\frac{J}{yg\°C} )(19.60-23.00)\°C\\\\Q_{rxn}=3219.25J[/tex]
Also, we can say the the heat released by the solution was -3219.25 J.
Best regards!
4. Given that 4NH3 + 5O2 4NO + 6H2O, if 4.23 x 1022 molecules NH3 were made to react with an excess of oxygen gas, how many molecules of NO would form?
5. If 0.433 moles of sulfur react with 0.500 moles of chlorine, how many moles of disulfur dichloride are produced? Which reactant is the limiting reactant and which is the reactant in excess?
S8(l) + 4Cl2(g) 4S2Cl2(l)
6. How many grams of Fe2O3 are produced when 2.30x10^24 molecules of O2 are reacted?
7. 3.50 g of potassium reacts with water to produce potassium hydroxide and hydrogen gas. Calculate the mass of potassium hydroxide produced. The unbalanced equation is: K + H2O KOH + H2
Please help as much as possible!
Answer:
Explanation:
Given Rxn => 4NH₃ + 5O₂ => 4NO + 6H₂O
Given data => 4.23 x 10²² molecules NH₃ => ? molecules NO
Approach: Convert given value in molecules to moles, solve for moles NO by equation ratios in balanced equation. Finish by multiplying moles of NO by Avogadro's Number (= 6.02 x 10²³ molecules/mole) to obtain molecules of NO.
moles NH₃ = 4.23 x 10²² molecules NH₃ / 6.023 x 10²³ molecules/mole
= 0.0703 mole NH₃
From equation stoichiometry of balanced equation 4 moles NH₃ gives 4 moles NO. Then 0.0703 mole NH₃ => 0.0703 mole NO b/c coefficients are equal in balanced equation.
∴molecules of NO = 0.0703 mole NO x 6.03 x 10²³ molecules NO/mole NO
= 4.23 x 10²² molecules of NO.
The remaining problems can be worked much in the same way. Convert given data to moles (if not already expressed in terms of moles), apply equation ratios to calculate needed substance in moles. Finish by converting calculated moles to desired dimension.
Hints for remaining problems:
Divide given moles of reactant substances by respective coefficients, the smaller value is the limiting reactant. Work problem based on moles (not the divide value. That's just for ID of Limiting Reactant). All other reactants will be in excess.
for problem 5 ...
Given 8S(l) + 4Cl₂(g) => 4S₂Cl₂(l)
Given: 0.433mole 0.500mole
LR 0.433/8 0.500/4
= 0.054 = 0.125
Limiting Reactant => Sulfur
Work problem from given 0.433 mole sulfur. Cl₂ will be in excess on completion of rxn.
Summary:
- convert data to moles
- divide mole values calculated by respective coefficient => smaller value is limiting reactant.
- use mole ratios to determine results, NOT the divided by value <=> this is only for ID of limiting reactant.
If ya need more, put question in comments. I'll get it. Now, If you do need additional input, before I do I will ask if you followed the hint suggestions, and your calculation results. Good luck :-)
What is the percent yield if 108.40 g O2 reacts with excess NH3 according to the balanced equation below and the actual yield is found to be 203.50 grams of H2O?
4 NH3 + 5 O2 → 4 NO + 6 H2O
Answer:
To express the efficiency of a reaction, you can calculate the percent yield using this formula: %yield = (actual yield/theoretical yield) x 100. A percent yield of 90% means the reaction was 90% efficient, and 10% of the materials were wasted (they failed to react, or their products were not captured).
Explanation:
Consider the following data on some weak acids and weak bases
acid
Ka
name formula
acetic acid
HCH3CO2
1.8 x10−5
hydrocyanic acid
HCN
4.9 x 10−10
base
Kb
name formula
pyridine
C5H5N
1.7 x 10−9
ammonia
NH3
1.8 x 10−5
Use this data to rank the following solutions in order of increasing pH. In other words, select a '1' next to the solution that will have the lowest pH, a '2' next to the solution that will have the next lowest pH, and so on.
a. 0.1M NaCH3CO2
b. 0.1M NH4Br
c. 0.1M NaBr
d. 0.1M KCN
Answer:
b < c < a < d
Explanation:
The weak acid with the lowest pKa will be the most acidic. In the other way, the conjugate base which the acid is weak will be strong.
The weak base with the lowest pKb will be the most basic. And the conjugate base of the weak base will be a strong acid.
Ka Acetic acid = 1.8x10-5
Ka HCN = 1.9x10-10
Kb pyridine = 1.7x10-9
Kb NH3 = 1.8x10-5
NH4Br is the conjugate base of a weak base. That means is a strong acid.
NH4Br has the lowest pH
NaBr is the conjugate base of a strong acid, HBr. That means NaBr is neutral
The most basic between the conjugate base of the acetic acid, NaCH3CO2 and KCN is KCN because the acetic acid is the stronger acid regard to HCN.
The rank is:
NH4Br < NaBr < NaCH3CO2 < KCN
b < c < a < dIt takes 53.0 J to raise the temperature of an 11.0 g piece of unknown metal from 13.0∘C to 24.3 ∘C. What is the specific heat for the metal?
Answer:
51 = ( 8.2/1000)Kg ×S (11.5)
51×1000= 8.2 (11.5)S
S = 51000/94.3
S = 540.8 J/kg K
Explanation:
What is the mass of 7.004 x 1023 molecules of calcium chloride?
Answer:
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What mass of NaCrO2 can be obtained from the reaction of 7.40g Cr(OH)3 with 7.60g NaOH in the following reaction: CrOH3+NaOH==>NaCrO2+2H2O
Explanation:
7.60 g of NaOH = 7.6/40 = 0.19 moles.
Reaction is 1:1 so NaOH in excess and Cr(OH)3 is limiting reactant.
You will get maximum of 0.0718 moles of NaCrO2 which is 0.0718*107 = 7.69 g
The mass of NaCrO₂ that can be obtained from the reaction is 14.92 grams.
To determine the mass of NaCrO₂ obtained, we need to calculate the molar mass and stoichiometry of the reaction.
Calculate the molar mass of Cr(OH)₃ and NaOH:
Molar mass of Cr(OH)₃ = 52.00 g/mol (chromium: 52.00 g/mol, oxygen: 16.00 g/mol, hydrogen: 1.01 g/mol)
Molar mass of NaOH = 39.99 g/mol (sodium: 22.99 g/mol, oxygen: 16.00 g/mol, hydrogen: 1.01 g/mol)
Determine the limiting reagent:
Convert the mass of Cr(OH)₃ to moles: 7.40 g Cr(OH)₃ * (1 mol / 52.00 g) = 0.1423 mol Cr(OH)₃
Convert the mass of NaOH to moles: 7.60 g NaOH * (1 mol / 39.99 g) = 0.190 mol NaOH
The stoichiometry of the reaction tells us that 1 mol of Cr(OH)₃ reacts with 1 mol of NaOH to produce 1 mol of NaCrO₂.
Compare the moles of Cr(OH)₃ and NaOH to determine the limiting reagent:
Cr(OH)3: 0.1423 mol
NaOH: 0.190 mol
Since Cr(OH)₃ has fewer moles, it is the limiting reagent.
Calculate the mass of NaCrO₂ produced:
The molar mass of NaCrO₂ is 105.00 g/mol (sodium: 22.99 g/mol, chromium: 52.00 g/mol, oxygen: 16.00 g/mol)
The stoichiometry tells us that 1 mol of Cr(OH)₃ produces 1 mol of NaCrO₂.
Therefore, the mass of NaCrO₂ obtained is:
0.1423 mol Cr(OH)₃ * (105.00 g NaCrO₂ / 1 mol Cr(OH)₃) = 14.92 g NaCrO₂
Thus, the mass of NaCrO₂ that can be obtained from the reaction is 14.92 grams.
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I need to know what the question is asking please help
Answer: What events create the heaviest elements?
I would Select:
Neutron Star Collissions
Supernova
How much does REAL carbon fiber cost ? lets say as big as a piece of paper
Answer:
Today, the average total production cost of “standard modulus” carbon fiber is in the range of $7-9 per pound.
If you have 4 molecules of FeCl3 and an unlimited supply of NaOH, how
many molecules of NaCl can you produce given the following balanced
equation?
FeCl3 + 3NaOH --> Fe(OH)3 + 3NaCl
Answer:
12 molecules of NaCl
Explanation:
The term "unlimited supply of NaOH" means that NaOH is the reactant in excess hence FeCl3 is the limiting reactant that controls the amount of product formed.
Thus;
From the balanced reaction equation;
1 molecule of FeCl3 yields 3 molecules of NaCl
Hence;
4 molecules of FeCl3 yields 4 * 3/1 = 12 molecules of NaCl
In both industry and research there are often times when one particular component of a mixture needs to be separated from a solution. Maybe it is a rare metal that is dissolved in a mixture of minerals. Maybe it is a particular protein from lysed plant cells. If the desired component is volatile, distillation could be used. But if the goal is to separate ions in solution, fractional precipitation is preferred.
a. True
b. False
Answer:
a. True
Explanation:
Distillation process is a process that is used to separate the components or the substances from the liquid mixtures by using selectively boiling and condensation.
While fractional precipitation is a process which separates the ions from solution based on the different solubilities.
Therefore, the answer is true.
What is the mass in grams of 7.5 mol of C8H18?
Answer:
[tex]\boxed {\boxed {\sf 856.74 \ g \ C_8H _{18}}}[/tex]
Explanation:
To convert from grams to moles, the molar mass is used. These values tells us the grams in 1 mole of a substance. They can be found on the Periodic Table (they are equivalent to the atomic masses, but the units are grams per mole).
We are given the compound C₈H₁₈. Look up the molar masses of the individual elements.
Carbon (C): 12.011 g/mol Hydrogen (H): 1.008 g/molNotice there are subscripts that tell us the number of atoms of each element. We must multiply the molar masses by the subscripts.
C₈: 8(12.011 g/mol)=96.088 g/mol H₁₈: 18(1.008 g/mol)=18.144 g/molAdd these 2 values together to find the molar mass of the whole compound.
C₈H₁₈: 96.088 g/mol +18.144 g/mol=114.232 g/molUse this number as a ratio.
[tex]\frac{ 114.232 \ g \ C_8H_{18}}{1 \ mol \ C_8H_{18}}[/tex]
Multiply by the given number of moles: 7.5
[tex]7.5 \ mol \ C_8H_{18}*\frac{ 114.232 \ g \ C_8H_{18}}{1 \ mol \ C_8H_{18}}[/tex]
The moles of C₈H₁₈ will cancel each other out.
[tex]7.5 *\frac{ 114.232 \ g \ C_8H_{18}}{1}[/tex]
[tex]7.5 *{ 114.232 \ g \ C_8H_{18}}[/tex]
[tex]856.74 \ g \ C_8H _{18}[/tex]
7.5 moles of C₈H₁₈ is equal to 856.74 grams of C₈H₁₈
In the graph above, what is the relationship between volume and temperature? Does this data support Charles' Law?
Hint: is it a direct or inverse relationship? How does volume change with temperature changes?
Answer:
No the graph does not support Charles' Law. Both volume and temperature increase so it would be a direct relationship.
Explanation:
The direct transfer of thermal energy between particles of
matter that are touching is called
Answer:
conduction
Explanation:
Si tengo 56 gramos de amoniaco gaseoso (NH3) ¿Cuántos moles y moléculas (entidades elementales) podré obtener?
Answer: 56 grams of gaseous ammonia (NH3), has 3.28 moles and [tex]19.80 \times 10^{23}[/tex] molecules.
Explanation:
Given: mass of [tex]NH_3[/tex] = 56 g
Molar mass of [tex]NH_3[/tex] is 17.03 g/mol.
As moles of a substance are its mass divided by the molar mass. Therefore, moles of [tex]NH_3[/tex] are calculated as follows.
[tex]No. of moles = \frac{mass}{molar mass}\\= \frac{56 g}{17.03 g/mol}\\= 3.28 mol[/tex]
According to the mole concept, 1 mole of every substance contains [tex]6.022 \times 10^{23}[/tex] molecules. Hence, number of molecules present in 3.28 moles of [tex]NH_3[/tex] are calculated as follows.
[tex]No. of molecules = no. of moles \times 6.022 \times 10^{23}\\= 3.28 mol \times 6.022 \times 10^{23}\\= 19.80 \times 10^{23}[/tex]
Therefore, we can conclude that 56 grams of gaseous ammonia (NH3), has 3.28 moles and [tex]19.80 \times 10^{23}[/tex] molecules.