Chemistry 12 Test

Question 1

The coefficients of a balanced chemical equation indicate the relative number of……of reactants and products.

Answer 1

Moles

Question 2

All stoichiometric calculations begin with a…….

Answer 2

Balanced equation

Question 3

Only….and….are conserved in every reaction,moles,volumes, and representative particles may not be.

Answer 3

Mass and atoms

Question 4

In solving stoichiometric problems, conversion factors relating moles of reactants to…..of products are used.

Answer 4

Moles

Question 5

If you assume….., the balanced equation also tells you about the volumes of gases.

Answer 5

Standard temperature and pressure

Question 6

Stoichiometry

Answer 6

The calculations of quantities in chemical reactions

Question 7

Product

Answer 7

A substance formed in a chemical reaction

Question 8

Coefficient

Answer 8

Gives the relative number of molecules involved in a reaction

Question 9

6.02 x 10 (23)

Answer 9

Avogadro’s number

Question 10

0 degrees Celsius, 101.3 kPa

Answer 10

STP

Question 11

Mole ratios from balanced equations may be used to solve problems with other units such as numbers of…..and…..of gases at STP.

Answer 11

Particles and volume

Question 12

The…..from the balanced equation are used to write conversion factors called……

Answer 12

Mole ratios

Question 13

These conversion factors are used to calculate the numbers of moles of…….from a given number of moles of……..

Answer 13

Product; reactant

Question 14

In mass-mass calculations, the molar mass is used to convert mass to…..

Answer 14

The number of moles unknown

Question 15

The coefficients in a balanced chemical equation can be used to form mole ratios relating reactants to products.
At,st,or nt?

Answer 15

AT

Question 16

The coefficients in a balanced chemical equation tell the relative volumes of reactants and products, expressed in any suitable unit of volume.
At,st,or nt?

Answer 16

ST

Question 17

To calculate the mass of a molecule in grams, you can use the molar mass and Avagadro’s number.
At,st,or nt?

Answer 17

AT

Question 18

Because the mass of the reactants equals the mass of the products of a reaction, the number of moles will be conserved.
At,st,or nt?

Answer 18

ST

Question 19

If the ratio of molecules in the reaction 2 A2+B2->2 A2 is 2:1:2, we can predict that 4 molecules of A2 react with 2 molecules B2 to produce 4 molecules of A2B.
At,st,or nt?

Answer 19

AT

Question 20

One mole of any gas occupies a volume of 22.4L.

At,st,or,nt?

Answer 20

ST

Question 21

In mass-mass calculations, the molar mass is used to convert mass to moles.
At,st,or nt?

Answer 21

AT

Question 22

In a volume-volume problem, the 22.4L/ mol factors always cancel out.
At,st,or nt?

Answer 22

AT

Question 23

In stoichiometric problems, volume is expressed in terms of liters.
At,st,or nt?

Answer 23

ST

Question 24

For a mass-mole problem, the first conversion from mass to moles is skipped.
At,st,or nt?

Answer 24

AT

Question 25

For a mass-mass problem, the first conversion is from moles to mass. At,st,or nt?

Answer 25

NT

Question 26

Because mole ratios from balanced equations are exact numbers, they do not enter into determination of significant figures. At,st,or nt?

Answer 26

AT