Question

Given the following unbalanced thermochemical equation, how much heat will be released from the combustion of 45.5 grams of CH4 in an excess of oxygen gas? CH4(g) + 2O2(g) → CO2(g) + 2H2O(l) + 890 kJ

Answer 1

-2530kJ

Step-by-step explanation:

45.5*16*890=2530

• 16 is from the mass of CH4
• the answer is negative because heat is on the product's side

Answer 2

CH4 + 2O2 → CO2 + 2H2O + 890 kJ

MM of CH4 = (12.01 + 4x1.008) g/mol = 16.04 g/mol

Moles of CH4 = 45.5 g CH4 x (1 mol CH4/16.04 g CH4) = 2.837 mol CH4

q = 2.837 mol CH4 x (890 kJ/1 mol CH4) = 2520 kJ