What mass of water (H2O) is formed when 4.6 g of methane (CH4) is burned in oxygen (O2)?

We implement the solution:
1. By the condition of the problem, we write:
m = 4.6 g. X g. -?
СН4 + 2О2 = СО2 + 2Н2О + Q – combustion of methane, heat, carbon dioxide and water are released;
2. Calculations:
M (CH4) = 16 g / mol.
M (H2O) = 18 g / mol.
Y (CH4) = m / M = 4.6 / 16 = 0.29 mol.
3. Proportion:
0.29 mol (CH4) – X mol (H2O);
-1 mol -2 mol hence, X mol (H2O) = 0.29 * 2/1 = 0.58 mol.
4. Find the mass of the product:
m (H2O) = Y * M = 0.58 * 18 = 10.44 g.
Answer: the mass of water is 10.44 g.