What volume of hydrogen is formed during the complete decomposition of 40 g of methane

What volume of hydrogen is formed during the complete decomposition of 40 g of methane, if the volume fraction of the hydrogen yield was 70%?

1.Let’s find the amount of methane substance by the formula:

n = m: M,

M (CH4) = 12 + 1 × 4 = 16 g / mol.

n = 40 g: 16 g / mol = 2.5 mol.

2. Let’s compose the reaction equation for the decomposition of methane.

CH4 = C + 2 H2.

According to the reaction equation, from 1 mole of methane, 2 moles of hydrogen are obtained, the quantitative ratios are 1: 2. The amount of hydrogen substance will be 2 times more than the amount of methane.

n (H2) = 2 × 2.5 mol = 5 mol.

3.Let’s find the volume of hydrogen by the formula:

V = Vn n, where Vn is the molar volume of gas, equal to 22.4 l / mol, and n is the amount of substance.

V = 22.4 L / mol × 5 mol = 112 L.

112 liters obtained by theory.

By the condition of the problem, the volume fraction of the hydrogen yield was 70%.

Find the volume of hydrogen, which is 70%.

112 l – 100%,

V l – 70%,

V = (70% × 112 L): 100% = 78.4 L.

Or it can be determined by the formula:

Ɣ = (¥ pr: ¥ theoretical) × 100%

Volume fraction = Volume fraction (practical): Volume fraction (theoretical) × 100%.

Answer: 78.4 liters.