Answer:
it may lead to read false measurements
while in an experiment.
that's what I think.
What is the difference between melting and burning a substance? Is mass conserved in either process?
Answer:
Explanation:
First Question:
Melting is a physical process that involves the phase transition of a substance from its solid to its liquid state. Burning, on the other hand, is a chemical process that involves a substance being broken down and changed into different substances. It's still the same substance, though: water.
Second Question:
Mass is therefore never conserved because a little of it turns into energy (or a little energy turns into mass) in every reaction. But mass+energy is always conserved. Energy cannot be created out of anything.
Hi I of the following compounds is an aldehyde?
Answer:
cpd 2
Explanation:
aldehyde is such a cpd which contains an alkyle gp with the formula R-CH=O
Functional group can be interconverted into each other by the means of suitable reagent. Functional group are responsible for the chemical and physical properties of a compound. Therefore the correct option is option 2 that is having group R-CHO.
What is functional group?A group of atoms forming a component of a molecule that accounts for a particular function or chemical behavior is called a functional group. There are so many functional group in organic chemistry.
The list of functional groups with their corresponding formulas can be given as
Carboxylic group COOH
Alcoholic group OH
Ammine group NH₂
Ketonic group R-CO_R
Aldehydic group R-CHO
Thiol group R-S-H
Cyanide group -CN
Therefore the correct option is option 2 that is having group R-CHO.
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HELPP
explain the difference between molecular and empirical formulas. Which types of compounds are described by the terms formula mass and molecular mass. Use an example to show the steps in calculating the formula mass for K2CO3
Answer:
In the previous section, we discussed the relationship between the bulk mass of a substance and the number of atoms or molecules it contains (moles). Given the chemical formula of the substance, we were able to determine the amount of the substance (moles) from its mass, and vice versa. But what if the chemical formula of a substance is unknown? In this section, we will explore how to apply these very same principles in order to derive the chemical formulas of unknown substances from experimental mass measurements.
Explanation:
tally. The results of these measurements permit the calculation of the compound’s percent composition, defined as the percentage by mass of each element in the compound. For example, consider a gaseous compound composed solely of carbon and hydrogen. The percent composition of this compound could be represented as follows:
\displaystyle \%\text{H}=\frac{\text{mass H}}{\text{mass compound}}\times 100\%%H=
mass compound
mass H
×100%
\displaystyle \%\text{C}=\frac{\text{mass C}}{\text{mass compound}}\times 100\%%C=
mass compound
mass C
×100%
If analysis of a 10.0-g sample of this gas showed it to contain 2.5 g H and 7.5 g C, the percent composition would be calculated to be 25% H and 75% C:
\displaystyle \%\text{H}=\frac{2.5\text{g H}}{10.0\text{g compound}}\times 100\%=25\%%H=
10.0g compound
2.5g H
×100%=25%
\displaystyle \%\text{C}=\frac{7.5\text{g C}}{10.0\text{g compound}}\times 100\%=75\%%C=
10.0g compound
7.5g C
×100%=75%
Indicate how CaCO3 neutralizes soil acidity. In other words, indicate how calcium carbonate chemically removes hydrogen from soil solution.
Answer:
Soil acidity can be corrected easily by liming the soil, or adding basic materials to neutralize the acid present. ... As lime dissolves in the soil, calcium (Ca) moves to the surface of soil particles, replacing the acidity. The acidity reacts with the carbonate (CO3) to form carbon dioxide (CO2) and water (H2O).
Explanation:
The
is the wind system responsible for the movement of weather from west to east across most of the continental United States
A
polar easterlies
B
prevailing westerlies
C
trade winds
Answer:
Westerlies are prevailing winds that blow from the west at midlatitudes. They are fed by polar easterlies and winds from the high-pressure horse latitudes, which sandwich them on either side.Nov 15, C answer
45.0 g of CaCl2 are dissolved in enough water so that the molarity of the solution is 1.15 M. What is the volume in mL of the solution?
Answer:
[tex]\boxed {\boxed {\sf 353 \ mL}}[/tex]
Explanation:
We are asked to find the volume in milliliters of a solution, given the mass of solute and molarity of the solution.
Molarity is a measure of concentration in moles per liter.
[tex]molarity = \frac {moles \ of \ solute}{liters \ of \ solution}[/tex]
1. Moles of SoluteWe are given the mass of the solute. We must convert the mass to moles using the molar mass (the mass of 1 mole of a substance). These values are found on the Periodic Table. They are equal to the atomic masses, but the units are grams per mole instead of atomic mass units.
Look up the molar masses of the individual elements in calcium chloride.
Ca: 40.08 g/mol Cl: 35.45 g/molThe chemical formula, CaCl₂, has a subscript of 2. There are 2 moles of chlorine in 1 mole of calcium chloride. We must multiply chlorine's molar mass by 2 before adding calcium's molar mass.
Cl₂ = 35.45 *2 = 70.9 g/mol CaCl₂= 40.08 + 70.9 = 110.98 g/molSet up a conversion factor using the molar mass.
[tex]\frac {110.98 \ g \ CaCl_2}{1 \ mol \ CaCl_2}[/tex]
Multiply by 45.0 grams of calcium chloride.
[tex]45.0 \ g \ CaCl_2 *\frac {110.98 \ g \ CaCl_2}{1 \ mol \ CaCl_2}[/tex]
Flip the conversion factor so the units of grams of calcium chloride cancel.
[tex]45.0 \ g \ CaCl_2 *\frac{1 \ mol \ CaCl_2} {110.98 \ g \ CaCl_2}[/tex]
[tex]45.0 \ *\frac{1 \ mol \ CaCl_2} {110.98}[/tex]
[tex]\frac {45.0}{110.98} \ mol \ CaCl_2= 0.405478465 \ mol \ CaCl_2[/tex]
2. Liters of SolutionNow we can find the liters of solution.
[tex]molarity = \frac {moles \ of \ solute}{liters \ of \ solution}[/tex]
molarity = 1.15 mol CaCl₂/L moles of solute = 0.405478465 mol CaCl₂liters of solution =xSubstitute the values into the formula.
[tex]1.15 \ mol \ CaCl_2/L = \frac{0.405478465 \ mol \ CaCl_2}{x}[/tex]
Cross multiply.
[tex]\frac {1.15 \ mol \ CaCl_2 /L}{1}= \frac{0.405478465 \ mol \ CaCl_2}{x}[/tex]
[tex]{1.15 \ mol \ CaCl_2 /L}*x= {0.405478465 \ mol \ CaCl_2} * 1[/tex]
Divide both sides of the equation by 1.15 moles of calcium chloride to isolate the variable x.
[tex]\frac {1.15 \ mol \ CaCl_2/L *x}{1.15 \ mol \ CaCl_2 /L}= \frac{0.405478465 \ mol \ CaCl_2 * 1 }{1.15 \ mol \ CaCl_2/L }[/tex]
[tex]x=\frac{0.405478465 \ mol \ CaCl_2 * 1 }{1.15 \ mol \ CaCl_2 /L}[/tex]
The units of moles of calcium chloride cancel.
[tex]x=\frac{0.405478465 }{1.15 \ L }[/tex]
[tex]x=0.35258997 \ L[/tex]
3. Convert to millilitersThere are 1000 milliliters in 1 liter.
[tex]\frac {1000 \ mL}{1 \ L}[/tex]
[tex]0.35258997 \ L * \frac{1000 \ mL}{ 1 \ L}[/tex]
[tex]0.35258997 * 1000 \ mL=352.58997 \ mL[/tex]
The original measurements of mass and molarity have 3 significant figures, so our answer must have the same. For the number we found, that is the ones place. The 5 in the tenth place tells us to round the 2 up to a 3.
[tex]353 \ mL[/tex]
The volume of the solution is approximately 353 milliliters.
Plants exchange carbon dioxide, water, and oxygen with their surrounding environment through openings in their ________ called _________.
A.
leaves, xylem
B.
roots, guard cells
C.
leaves, stomata
D.
stems, sori
Limestone is used in industry as a raw material in the production of slaked Ca (OH) 2.
1) Write the equations of the chemical reactions that characterize the transformations carried out in the production process!
CaCO3 -> CaO -> Ca (OH) 2
The first reaction equation is how calcium oxide can be obtained from calcium carbonate.
The second reaction equation - how calcium oxide can be obtained from calcium oxide.
Answer:
i k ow its not the exact anwser but ih ope this helps
Explanation:
Energy plays a key role in chemical processes. According to the modern view of chemical reactions, bonds between atoms in the reactants must be broken, and the atoms or pieces of molecules are reassembled into products by forming new bonds. Energy is absorbed to break bonds, and energy is evolved as bonds are made. In some reactions the energy required to break bonds is larger than the energy evolved on making new bonds, and the net result is the absorption of energy. Such a reaction is said to be endothermic if the energy is in the form of heat. The opposite of endothermic is exothermic; in an exothermic reaction, energy as heat is evolved. The more general terms exoergic (energy evolved) and endoergic (energy required) are used when forms of energy other than heat are involved.
A great many common reactions are exothermic. The formation of compounds from the constituent elements is almost always exothermic. Formation of water from molecular hydrogen and oxygen and the formation of a metal oxide such as calcium oxide (CaO) from calcium metal and oxygen gas are examples. Among widely recognizable exothermic reactions is the combustion of fuels (such as the reaction of methane with oxygen mentioned previously).
When 0.717 g of sodium metal is added to an excess of hydrochloric acid, 7450 J of heat are produced. What is the enthalpy of the reaction as written?
2Na(s)+2HCl(aq)⟶2NaCl(aq)+H2(g)
Answer:
The enthalpy change of the reaction is 4.78 × 10⁴ J.
Explanation:
We are given that 0.717 g of sodium metal reacts with hydrochloric acid to produce 7450 J of heat.
Converting grams of sodium to moles:
[tex]\displaystyle 0.717 \text{ g Na} \cdot \frac{1 \text{ mol Na}}{22.99 \text{ g Na}} = 0.0312 \text{ mol Na}[/tex]
And dividing the amount of heat produced by the moles of sodium reacted yields:
[tex]\displaystyle \Delta H = \frac{7450 \text{ J}}{0.312 \text{ mol Na}} = 2.39 \times 10^4 \text{ J/mol Na}[/tex]
Because the given reaction has two moles of sodium metal, we can multiply the above value by two to acquire the enthalpy change of the given reaction:
[tex]\displaystyle \Delta H = 2\text{ mol Na}\left(2.39 \times 10^4 \text{ J/mol Na}}\right) = 4.78 \times 10^4 \text{ J}[/tex]
In conclusion, the enthalpy change of the reaction is 4.78 × 10⁴ J.
Methane (CH4) is used in laboratory burner. When 1 mole of methane burns at constant pressure, it produces 804 kJ of heat and does 3 kJ of work.Methane (CH4) is used in laboratory burner. When 1 mole of methane burns at constant pressure, it produces 804 kJ of heat and does 3 kJ of work.
The enthalpy ΔH of combustion is - 804 kJ. The change in internal energy ΔE of the reaction process is -801 kJ
The objective of this question is to determine the value of ΔH and ΔE of combustion is for 1 mole of methane.
If we look closely at the question, we will realize that at constant pressure, methane burns and produces heat of 804 kJ into the surroundings.
Since heat is released;
ΔH = -804 kJ
It also does a work of 3kJ, since work is done on the system
W = - 3kJ
According to the first law of thermodynamics;
ΔE = ΔH - W
ΔE = (-804 - (-3 )) kJ
ΔE = -801 kJ
Therefore, we can conclude that the in 1 mole of methane, the enthalpy ΔH of combustion is - 804 kJ. The change in internal energy ΔE of the reaction process is -801 kJ
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How does the structure of compounds determines the properties of the compounds?
All of these properties are due to the chemical structure of the compound. The chemical structure includes the bonding angle, the type of bonds, the size of the molecule, and the interactions between molecules. Slight changes in the chemical structure can drastically affect the properties of the compound.
Potassium metal reacts with water according to the following balanced equation.
2 K(s) + 2 H2O(l) — 2 KOH(aq) + H, (8)
If one mole of potassium reacts in this manner, how many moles of water are consumed?
Answer: 1 mole
Explanation:
One mole reacts because there is a 1:1 ratio between the potassium and water at the beginning of the equation. 2K+2H2O has a 1 to 1 ratio. If one potassium reacts there is one h2o that also reacts.
Taking into account the reaction stoichiometry, if one mole of potassium reacts, 1 mole of water are consumed.
Reaction stoichiometryIn first place, the balanced reaction is:
2 K + 2 H₂O → 2 KOH + H₂
By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:
K: 2 moles H₂O: 2 moles KOH: 2 moles H₂: 1 moleMoles of water consumedThe amount of water consumed is calculated from the following rule of three: if by stoichiometry 2 moles of K react with 2 moles of H₂O, 1 mole of K react with how many moles of H₂O?
[tex]amount of moles of H_{2} O=\frac{1 mole of Kx2 moles ofH_{2} O }{2 moles of K}[/tex]
amount of moles of H₂O= 1 mole
In summary, if one mole of potassium reacts, 1 mole of water are consumed.
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Hey :3 please help with this. Will mark brainlist if you’re right
Answer: 4
Explanation:
True or false? Suppose you have two identical birthday balloons, with one filled with the gas helium and the other blown up by you. Assuming they're both filled to the same amount, these balloons will have the same number of molecules.
Answer:
True!
Explanation:
Avogadro’s law means that if we compare the number of helium molecules and the number of air molecules needed to inflate the same balloon, we would find the numbers the same.
The balloon filled with helium air, and the one blown by oneself with the same amount of air have the equivalent number of molecules. Thus, the given statement is true.
What is the relation between moles and atoms?The moles are given as the mass of the compound with respect to the molar mass. According to the Avogadro's law, the 1 mole of a substance has the presence of the atoms equivalent to the Avogadro number.
In the balloons filled with oneself and individual there is same amount of gas, thus have same moles and thereby the number of molecules will be same in both the balloons. Thus, the given statement is true.
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Help with this pretty please!
Answer:
10
Explanation:
Basically same as last question but the number is before the compound :)
Question 3 of 10
Which event indicates an endothermic chemical reaction?
A. Decrease in temperature
B. Release of heat
C. Increase in thermal energy
D. Production of light
Plz help
Answer:
A. Decrease in temperature
Explanation:
The statement indicates an endothermic chemical reaction is "Decrease in temperature".
What is endothermic reaction?Endothermic reactions generate products by absorbing heat energy from the environment.
The temperature of the reaction mixture rises as energy is released in an exothermic process. The temperature drops when energy is absorbed in an endothermic reaction. A thermometer can be used to monitor temperature changes in the reaction mixture.
An endothermic reaction happens when the temperature of an isolated system drops while the temperature of its surroundings rises. The overall heat of reaction in endothermic reactions is positive (q > 0).
Hence the correct option is A.
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Copper is an example of?
Transition Metal
Noble Gases
Alkali Metal
Halogen
Answer:
Transition Metal
Explanation:
If you look at a periodic table, you can see that Cu is a transition metal.
Identify whether the following changes would generally increase or decrease the reaction rate. (3 points)
• Increasing the concentrations of reactants (0.5 point):
• Increasing the temperature (0.5 point):
• Increasing the pressure (0.5 point):
• Shining light on the reaction (0.5 point):
• Increasing the activation energy (0.5 point):
Answer: (1) increase(2) increase (3) increase (4) increases(5) decrease
Explanation:so basically anything you do will make the reaction go faster except like increasing the activation energy for example
The correct answers are as follows
Increase Increase Increase Increase DecreaseWhat is Reaction rate?It is the measure of the change in concentration of the reactants or the change in concentration of the products per unit time.The speed of a chemical reaction is the change in concentration of a substance divided by the time interval during which this change is observed.
What will happen to reaction rate if we do the following?The reaction rate will increase on Increasing the concentrations of reactants.The reaction rate will increase on Increasing the temperature. The reaction rate will increase on Increasing the pressure.The reaction rate will increase on Shining light on the reaction.The reaction rate will decrease on Increasing the activation energy .
Hence Except Activation energy the reaction rate will increase
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375cm³ of a gas has a pressure of 770 mm Hg, find it Volume if the pressure is reduced to 750 mm Hg
Answer:
Explanation:
Givens
v1 = 375 cm^3
P1 = 770 mm Hg
V2 = ?
P2 = 750 mm Hg
Formula
V1 P1 = V2 P2
Solution
375 * 770 = V2 * 750 Combine the left
288750 = V2 * 750 Divide both sides by 750
288750/750 = V2
V2 = 385
Which one of these is not an important structural feature found by the number of
electron rich regions
Hybridization
Bond Angles
Electronegativity
Electron Geometry
Answer:
Electronnegativity
Explanation:
There are three important structural features: Hybridization, Bond angels, and Electron Geometry.
The not so important structural feature found by the number of electron rich regions is electronegativity. Hence option c is correct.
What are structural feature?Structural feature is defined as the modeled as a directed acyclic graph (DAG), with the variable names as pathways and the variable values as nodes. The study of the construction of biological molecules is known as structural biology. Scientists study molecules in three dimensions using a range of imaging techniques to examine how they are put together, how they work, and how they interact.
Electronegativity is defined as the propensity for atoms involved in covalent bonds to draw the bonding electrons. The negatively charged electrons are drawn to the positively charged protons in the nucleus. The electronegativity or attraction will rise with the number of protons in the nucleus. Therefore, in a row of the periodic table, electronegativity rises from left to right.
Thus, the not so important structural feature found by the number of electron rich regions is electronegativity. Hence option c is correct.
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how many grams of H20 can be formed from 0.996 g C8 H18?
aufbau principle
what is the meaning of the principle
Answer:
The meaning of this principle is building-up.
Explanation:
The Aufbau principle asserts that electrons occupy lower-energy atomic orbitals before filling higher-energy ones (Aufbau is German for "building-up") (Aufbau is German for "building-up"). By using this method, we may forecast the electron configurations for atoms or ions.
Nancy rides her bike 114.8 miles in 8.2 hours. What is her average speed in miles per hour
The answer to the question is 14 no cap
One type of sunburn occurs when skin is exposed
to UV light of wavelength in the vicinity of 315 nm.
What is the energy of a photon of this wavelength?
Answer:
E = 6.27 × 10⁻²³ Joules
Explanation:
E = h (Plancks constant) × f (frequency)
(Plancks constant = 6.63 × 10⁻³⁴ J×s)
f = λ × c (used to find frequency so you can satisfy energy equation)
*Have to find wavelength in meters to multiply by speed of light*
1. f = (3.15 × 10⁻⁷ m) × (3 × 10⁸ m/s)
2. f = 9.45 × 10¹⁰ s
3. E = (6.63 × 10⁻³⁴ J×s [Plancks constant]) × (9.45 × 10¹⁰ s)
E = 6.27 × 10⁻²³ Joules
Identify the movements of the glenohumeral joint that occur with contraction of the infraspinatus and teres minor.
Answer: adduction of the arm
lateral rotation of the arm
Explanation:
What is a solution?
A. A mixture of two solids blended together
B. A compound that is in liquid and gas states
C. A liquid with something dissolved in it
OD. A clear liquid with nothing dissolved in it
Why do some hockey players go flying when they are checked?
how to draw ethyl structural formula?
Answer:
c2H5
Explanation:
H. H
|. |
C-C- H
|. |
H. H
Calculate the mass of 5.3 moles of chloric acid (HClO3). Explain the process or show your work by including all values used to determine the answer.
Answer:
447.64 grams
Explanation:
To find the mass when given moles, it is a pretty simple process.
I start by finding the molar mass of chloric acid, which comes out to 84.46 grams/mol. To find the MM (molar mass), you just take the mass of each element in the molecule from the periodic table and add them all together.
After this, you set up the equation by taking the moles given and multiplying it by the molar mass. This gives you the new value in grams (since we cancelled out the moles). I have attached my work below.
I hope this helps! :^)
The mass of 5.3 moles chloric acid has been 447.85 g.
The mass of 1 mole of a compound has been equivalent to the molar mass of the compound. The molar mass of a compound has been the sum of the constituent atoms in a formula unit.
The molar mass (mwt) of chloric acid has been given as:
[tex]mwt=m_H\;+\;m_C_l\;+\;(m_O\;\times\;3)[/tex]
By substituting the values for the mass of constituent atoms, the molar mass has been given as:
[tex]mwt=1\;+\;35.5\;+\;16\;\times\;3\\mwt=36.5\;+\;48\\mwt=84.5[/tex]
The molar mass of chloric acid has been 84.5 g/mol.
The mass of 1 mole of chloric acid has been 84.5 g/mol. The mass of 5.3 moles chloric acid has been:
[tex]\rm 1\;mol=84.5\;g\\5.3\;mol=5.3\;\times\;84.5\;g\\5.3\;mol=447.85\;g[/tex]
The mass of 5.3 moles chloric acid has been 447.85 g.
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help! giving brainliest
Answer:
sorry wala din akong sagot niyan sorry talaga