Question

How much heat is released from burning 42.6 grams of CH4?

CH4 (g) + 2 O2 (g) ---> CO2 (g) + 2 H2O (l) delta H = -890.4 kJ

Answer 1

-2.37 × 10³ kJ

Step-by-step explanation:

Let's consider the following thermochemical equation.

CH₄(g) + 2 O₂(g) ⇒ CO₂(g) + 2 H₂O(l) ΔH = -890.4 kJ

Step 1: Calculate the moles corresponding to 42.6 g of methane

The molar mass of CH₄ is 16.04 g/mol. We will use this to calculate the moles corresponding to 42.6 g of CH₄.

`42.6g * (1mol)/(16.04g) = 2.66mol`

Step 2: Calculate the heat released from burning 2.66 moles of methane

According to the thermochemical equation, 890.4 kJ are released from burning 1 mol of methane. Then,

`(-890.4kJ)/(1molCH_4) * 2.66molCH_4 = -2.37 * 10^(3) kJ`