What is the size range of particles in a colloid? between 100 nm and 1000 nm between 1000 nm and 2000 nm between 1 nm and 10 nm between 1 nm and 1000 nm

C) 182g

Explanation:

Based on the reaction:

C₂H₂ + ⁵/₂O₂ → 2CO₂ + H₂O

300kCal are produced per mole of C₂O₂.

As you want to vaporizate 210 moles of water:

210mol H₂O ₓ (10kCal / mol) = 2100kCal

These 2100kCal must come from the reaction of acetylene:

2100kCal × (1mol C₂H₂ / 300kCal) = 7 moles of C₂H₂

As molar mass of C₂H₂ is 26.04g/mol:

7 mol  × (26.04g / 1mol) = 182g of acetylene

C) 182g