Question

1. how many grams of o2 are needed to produce 157.4 g of co2 from the combustion reaction?

Explanation:

Step1: Write the combustion reaction equation

For the complete - combustion of a hydrocarbon (assuming complete combustion of a compound containing C and H to produce CO₂ and H₂O), the general reaction for the combustion of a carbon - containing fuel with oxygen to produce CO₂ is: C + O₂→CO₂ (simplified for carbon - based reaction considering CO₂ production). The molar mass of CO₂, M(CO₂)=12 + 2×16=44 g/mol, and the molar mass of O₂, M(O₂)=2×16 = 32 g/mol.

Step2: Calculate the number of moles of CO₂

The number of moles of CO₂, n(CO₂)=\frac{m(CO₂)}{M(CO₂)}, where m(CO₂) = 157.4 g. So, n(CO₂)=\frac{157.4\ g}{44\ g/mol}=3.577\ mol.

Step3: Determine the mole ratio between O₂ and CO₂

From the balanced chemical equation C + O₂→CO₂, the mole ratio of O₂ to CO₂ is 1:1, i.e., n(O₂)=n(CO₂).

Step4: Calculate the mass of O₂

The mass of O₂, m(O₂)=n(O₂)×M(O₂). Since n(O₂)=3.577 mol and M(O₂) = 32 g/mol, m(O₂)=3.577\ mol×32\ g/mol = 114.464 g.

Answer:

114.5 g (rounded to one decimal place)