Stoichiometry Quiz Honors

Welding torches use acetylene gas (C2H2) in combustion reactions. Write the balanced equation for the reaction. (6 pts)

• C2H2 + O2 → CO2 + H2O

• C2H2 + 5O2 → 2 CO2 + H2O

• C2H2 + O2 → 2 CO2 + 2 H2O

• 2C2H2 + 5O2 → 4CO2 + 2H2O

Welding torches use acetylene gas (C2H2) in combustion reactions. Determine the percent composition, by mass, of C2H2. (4 pts)

• 90% C, 10% H

• 98% C, 2% H

• 92.26% C, 7.743% H

• 95.5% C, 4.5% H

Welding torches use acetylene gas (C2H2) in combustion reactions. Using the balanced equation 2C2H2 + 5O2 → 4CO2 + 2H2O, determine the number of moles of water formed if you start with 12.00 moles of acetylene gas. (3 pts)

d

e

f

6.00 moles O2

9.00 moles H20

2 moles H20

2 moles O2

12.00 moles H2O

18.00 molesH20

Tags

NGSS.HS-PS1-7

Welding torches use acetylene gas (C2H2) in combustion reactions. Using the balanced equation 2C2H2 + 5O2 → 4CO2 + 2H2O, calculate the mass produced, in grams, of carbon dioxide if 1.75 moles of oxygen react completely. (4 pts)

c

d

e

f

g

h

4mol CO2

88.0 g

44.01 g

5 mol O2

1.75 mol O2

61.6 g CO2

1 mol CO2

77.0 g

Using the balanced combustion equation for acetylene, 2C2H2 + 5O2 → 4CO2 + 2H2O, determine the mass of oxygen gas needed to produce 180.0 grams of water. (5 pts)

a

b

c

d

e

f

g

18.02 g

180 g H20

5 mol O2

1 mol O2

32 g O2

1 mol H20

2 mol H2O

Tags

NGSS.HS-PS1-7

e

f

g

h

i

C8H8

C5H5

3(C2H2)

26.036 g

78.114 g

C6H6

4(C2H2)

C6H6

C4H4

3