(C) C21H44 can be cracked to produce ethene.
Cz1H44 — 3C2H4 + C15H32
Relative formula mass (M) of C21H44 = 296
Calculate the mass of C21H44 needed to produce 50.4 kg of ethene.

177.3kg C₂₁H₄₄

Explanation:

Based on the chemical reaction:

C₂₁H₄₄ → 3C₂H₄ + C₁₅H₃₂

Where 1 mole of C₂₁H₄₄ produce 3 moles of ethene, C₂H₄.

To solve this question we need to determine the moles of ethene in 50.4kg. 1/3 these moles are the moles of C₂₁H₄₄ that must be added:

Moles Ethene -Molar mass: 28.05g/mol-

50.4kg = 50400g * (1mol / 28.05g) = 1796.8 moles of ethene

Moles C₂₁H₄₄:

1796.8 moles of ethene * (1 mol C₂₁H₄₄ / 3 mol C₂H₄) = 589.93 moles C₂₁H₄₄

Mass C₂₁H₄₄:

589.93 moles C₂₁H₄₄ * (296g / mol) = 177283g =

1.solid

2.carbon dioxide

3.helium