Stoichiometry

Question 1

Stoichiometry is…

Answer 1

The relationship between the macroscopic and molecular level.

Question 2

Stoichiometry allows us to… #1

Answer 2

Calculate how much “stuff” can be produced in a reaction…

Question 3

Stoichiometry allows us to… #2

Answer 3

Calculate the relationship between any two components in a reaction.

Question 4

We use ________ to allow us to connect from the molecular level to the observable macroscopic level.

Answer 4

Moles

Question 5

Mole is just a number, that number is…

Answer 5

6.022 × 10^23

Question 6

6.022 × 10^23 is also known as…

Answer 6

Avogadro’s Number

Question 7

Balance the equation:
__N2+__O2🡪__N2O

Answer 7

2 N2+O2——->2 N2O

Question 8

Balance the equation:
__C6H14 + __O2 🡪 __CO2 + __H2O

Answer 8

2 C6H14 + 38 O2 🡪 12 CO2 + 14 H2O

Question 9

Balance the equation:
__FeCl3 + __NaOH 🡪 __Fe(OH)3 + __NaCl

Answer 9

FeCl3 + 3 NaOH 🡪 Fe(OH)3 + 3 NaCl

Question 10

How many moles of calcium nitrate are in 325g? Calcium nitrate = Ca(NO3)2

Answer 10

Molar mass of Ca(NO3)2 = 164.09 g/mol

                            1 mole Ca(NO3)2                                               325g Ca(NO3)2 x --------------------- = 1.98 mole Ca(NO3)2
                               164.09 g/mol

Question 11

How many moles of O atoms are in 2 mol Ca(NO3)2?

Answer 11

12 mol O atoms

Question 12

How many atoms are 12 mole O atoms?

Answer 12

7.2264 x 10^24

Question 13

Which of the following contains the largest number of molecules?
A. 1 mol CH4
B. 1 mol C2H6
C. 1 mol SO2
D. 1 mol CCl4
E. They all have the same number

Answer 13

E. They all have the same number

Question 14

Which of the following contains the largest number of molecules?
A. 10.0 g CH4
B. 10.0 g C2H6
C. 10.0 g SO2
D. 10.0 g CCl4
E. They all have the same number

Answer 14

A. 10.0 g CH4

Question 15

Study Stoichiometry Chart!

Answer 15

SLIDE 24-25

Question 16

How many moles of NH3 would be produced if 6 moles of H2 reacted with excess N2?
Write a balanced equation for this reaction.
A. NH3 🡪 N2 + H2
B. 2 NH3 🡪 N2 + 3 H2
C. N2 + H2 🡪 NH3
D. N2 + 3 H2 🡪 2 NH3

Answer 16

D

Question 17

How many grams of N2 are needed to react with H2 to produce 2.75 moles of NH3?

Answer 17

2.75 mol NH3 x ((1 mol N2)/(2 mol NH3)) x ((28g N2)/(1 mol N2))=
38.5g N2

Question 18

How many moles of NH3 would be produced if 6 moles of H2 reacted with 3 moles of N2?

Answer 18

6 mol H2 x ((2 mol NH3)/(3 mol H2)) = 4 mol NH3
+
3 mol N2 x ((2 mol NH3)/(1 mol N2) = 6 mol NH3
___________________________________________
10 mol

Question 19

When 6 mol H2 reacts with 3 mol N2,
4 mol NH3 is produced.
ALL of the limiting reactant (H2) is used up. How many moles of N2 remain at the end?

Answer 19

1 mol N2 = 3 mol N2 – 2 mol N2
4 mol NH3 × 1 mol N2 /2 mol NH3 = 2 mol N2

Question 20

The equation for a reaction is 2 S + 3 O2 🡪 2 SO3. Which is the limiting reactant?
A. S
B. O2
C. SO3
D. There is no limiting reactant

Answer 20

B.

Question 21

How many grams of carbon dioxide would be produced if 10 grams of methane are combusted in excess oxygen?

Answer 21

27.5 g

Question 22

What do we use to convert from grams of methane to moles of methane?
A. Stoichiometric ratio
B. Molar mass

Answer 22

B.

Question 23

What do we use to convert from moles of methane to moles of carbon dioxide?
A. Stoichiometric ratio
B. Molar mass

Answer 23

A.

Question 24

How many grams carbon dioxide would be produced if an excess of methane is combusted in 10 g oxygen?

Answer 24

10 g O2 × 1 mole O2 / 32 g O2 ×
1 mole CO2 / 2 mole O2 × 44 g CO2 / 1 mole CO2 = 6.9 g CO2

Question 25

If you had 10g of CH4 and 10g of O2, what is the maximum number of grams of CO2 that could be produced?

Answer 25

27.5

Question 26

In the previous example (O2), if only 5.0 g CO2 was produced, what is the percent yield?

A. 0.72%
B. 72%
C.1.38%
D.138%

Answer 26

Percent yield = (actual amount produced/theoretical amount) × 100

B.

Question 27

Final Review Video:

Answer 27

https://mediaspace.msu.edu/media/stoichiometry/1_9to3y8kv