Chapter 7: Chemical Quantities and Reactions

Question 1

1 mole =

Answer 1

6.02 x 10^23 items

Question 2

What are the two possible conversion factors for moles?

Answer 2

1 mole/6.02 x 10^23

6.02x10^23/ 1 mole

Question 3

How many COv2 molecules are in .50 mole of COv2?

Answer 3

step one: figure out proper conversion factor
step two:
.50 mole CO2 x 6.02x10^23 divided by 1 mole of CO2
step three: cross out “mole CO2” on left and right side, then multiple .50 x 6.02
Answer: 3.01 x 10^23 molecules of CO2

Question 4

Pause and do some mole conversion problems via internet or printed out sheet

Answer 4

:)

Question 5

What is the number of atoms in 2.0 moles of Al?

Answer 5

2.0 x 6.02 = 12.04 x 10^23. Move decimal to the left one time, drop 0 and 4, increase ^23 to ^24 Answer: 1.2 x 10^24 moles of Al

Question 6

Do the subscripts show the number of moles for each element?

Answer 6

Yes

Question 7

Aspirin, C9H8O4 has how many moles of each element? And each mole contains how many atoms?

Answer 7

C=9moles
H=8 moles
O=4 moles
one mole of any element = 6.02 x 10^23 atoms

Question 8

How many atoms of O are in .150 mole of aspirin? (C9H8O4)?

Answer 8

.150 x 4 = 0.6. Then, .6 x 6.02 x 10^23 = 3.61 x 10^23 atoms of O

Question 9

atomic mass of an element equals the ___ ____

Answer 9

molar mass

Question 10

1 mole of _____ has a mass of 22.99 grams

Answer 10

sodium

Question 11

1 mole of C atoms = _____ grams of C atoms (hint: periodic table shows atomic mass below symbol)

Answer 11

12.01

Question 12

What is the molar mass of Li2CO3?

Answer 12

separate each element into a conversion factor with the found molar mass. multiply the number of moles of each element by their atomic mass. Li2 x 6.941 = 13.88g of Li
C x 12.01= 12.01g of C
O3 x 16.00 = 48.00 g of O
Add all together for a molar mass of 73.89g

Question 13

Pause and complete some molar mass equations (g to moles and vice versa)

Answer 13

:)

Question 14

A box of table salt contains 737g or NaCl. How many moles of NaCl are present in the box?

Answer 14

Given: 737g NaCl
Need: moles of NaCl
First, find molar mass
1 mole of NaCl= 58.44g/mole (because 22.99+35.45=58.44g/mole)
then divide 737 grams by the molar mass of NaCl to get 12.6 moles NaCl.

Question 15

A sample of water has a mass of 59.8 grams. How many moles of water are in the sample?

Answer 15

We know there are 59.8 grams of water in this sample, and one mole of water = 18.02g/mole. Simply divide 59.8 by the molar mass of water. Answer is 3.318534 blah blah rounded up to 3.32 moles of H2O

Question 16

Balance __Al + __S –> AlS

Answer 16

2Al + 3S —> Al2-S3

Question 17

Explain balancing an equation

Answer 17

products and reactants must balance on either side. Coefficients in front of each element can be multiplied by the subscript following said element to equal the same amounts on the other side. Balance H and O ‘s last. Don’t be afraid to place higher coefficients than usual if 2/3/4 are not working. Some equations use 5’s and 7’s, but always ensure the coefficients in the end result are as low as you can go.

Question 18

Balancing equations with polyatomic ions. Explain what you do with the subscript attached to polyatomic ions

Answer 18

Na3PO4 + MgCl2 .... when you go to balance this first half the equation, don't count PO4 as separate elements (P: 1 and O: 4)
Na : 3
PO4: 1
Mg: 1
Cl:  2
---> Mg3 (PO4)2 + NaCl
Mg: 3
(PO4): 2
Na: 1
Cl: 1
Above is the correct way to write out what you see, do not multiply or lump (PO4)2 or put P: 4 and O:4

Question 19

Name the type of reaction.

2Mg + O2 –> 2MgO

Answer 19

Combination

Question 20

SO3 + H2O –> H2SO4

Answer 20

Combination

Question 21

Two or more reactants combine to yield a single product. This is a _____ reaction

Answer 21

Combination

Question 22

A reactant splits into two or more products. This is a _______ reaction

Answer 22

Decomposition

Question 23

One element replaces another element. This is a _________ reaction

Answer 23

single replacement

Question 24

Zn + 2HCL —> ZnCl + H2 is a _____ reaction

Answer 24

Single replacement

Question 25

Two elements replace each other. THis is a _________

Answer 25

double replacement

Question 26

In a _____ _____, a carbon containing compound burns in oxygen gas to form carbon dioxide and water. Energy is released as a product in the form of heat in this reaction.

Answer 26

Combustion reaction

Question 27

_____ _____ is colorless, odorless, and a poisonous gas.

Answer 27

Carbon dioxide

Question 28

CO2 ____ the amount of oxygen gas that can reach the cells

Answer 28

reduces

Question 29

Name the three conditions for a reaction to occur

Answer 29

• Collision
• Orientation
• energy

Question 30

Take a five minute break

Answer 30

(-:

Question 31

In an ______ reaction:

• heat is released
• the energy of the products is less than the energy of the reactants
• heat is a product

Answer 31

Exothermic

Question 32

In an _______ reaction,

• Heat is absorbed
• the energy of the products is greater than the energy of the reactants
• heat is a reactant

Answer 32

Endothermic

Question 33

The _____ _____ increases when temperature rises because the reacting molecules move _____, providing more collisions between molecules with energy of activation

Answer 33

Reaction rate, faster.

Question 34

The _____ ____ increases with increase in concentration of reactants

Answer 34

reaction rate

Question 35

A ______ increases the rate of a reaction but lowers the energy of activation

Answer 35

Catalyst