Question

How many grams of O2 are needed to react with 8.15 g of C2H2?

Answer 1

Answer:

25.08 grams of O₂ are needed to react with 8.15 g of C₂H₂.

Explanation:

The balanced reaction is:

2 C₂H₂ + 5 O₂ → 4 CO₂ + 2 H₂O

By reaction stoichiometry, the following amounts of moles of each compound participate in the reaction:

• C₂H₂: 2 moles
• O₂: 5 moles
• CO₂: 4 moles
• H₂O: 2 moles

The molar mass of each compound is:

• C₂H₂: 26 g/mole
• O₂: 32 g/mole
• CO₂: 44 g/mole
• H₂O: 18 g/mole

Then, by reaction stoichiometry, the following mass quantities of each compound participate in the reaction:

• C₂H₂: 2 moles* 26 g/mole= 52 g
• O₂: 5 moles* 32 g/mole= 160 g
• CO₂: 4 moles* 44 g/mole= 176 g
• H₂O: 2 moles* 18 g/mole= 36 g

Then you can apply the following rule of three: if by stoichiometry 52 grams of C₂H₂ react with 160 grams of O₂, 8.15 grams of C₂H₂ react with how much mass of O₂?

$mass of O_{2} =\frac{8.15 grams of C_{2} H_{2}*160 grams of O_{2} }{52 grams of C_{2} H_{2}}$

mass of O₂= 25.08 grams

25.08 grams of O₂ are needed to react with 8.15 g of C₂H₂.