Question

Methane (CH4), ammonia (NH3), and oxygen (O2) can react to form hydrogen cyanide (HCN) and water according to this equation:

Answer 1

The answer to your question is D. 24g

Answer 2

The grams  of  oxygen that are required  to produce 1  mole  of H₂O  is 16 g ( answer  B)

calculation

2 CH₄  + 2NH₃ +3 O₂ → 2HCN  + 6H₂O

step 1: use the mole ratio to find moles of O₂

from equation above the  mole ratio  of O₂: H₂O  is 3:6 therefore the moles of O₂  = 1 mole x3/6 =0.5 moles

step  2: find   mass of O₂

mass= moles x molar mass

from periodic table the molar mass  of O₂ = 16 x2= 32 g/mol

mass O₂ = 0.5 moles x 32 g/mol = 16 g (answer B)