Question

When the reaction below produces 11.6 g of ethylene, C₂H4 it produces 2.4 L of hydrogen

gas at 300 K. What is the pressure of the hydrogen gas?

2 CH4 -> C₂H4 + 2 H₂

Answer 1

8.35 atm.

Step-by-step explanation:

The given reaction is:

2 CH4 → C2H4 + 2 H2

From the balanced equation, we can see that for every mole of C2H4 produced, 2 moles of H2 are produced.

First, we need to find the number of moles of C2H4 produced:

Molar mass of C2H4 = 2(12.01 g/mol) + 4(1.01 g/mol) = 28.05 g/mol

Number of moles of C2H4 = 11.6 g / 28.05 g/mol = 0.413 mol

Since 2 moles of H2 are produced for every mole of C2H4, the number of moles of H2 produced is:

0.413 mol C2H4 × 2 mol H2 / 1 mol C2H4 = 0.826 mol H2

Now we can use the ideal gas law to find the pressure of H2:

PV = nRT

where P is pressure, V is volume, n is the number of moles, R is the gas constant (0.0821 L·atm/K·mol), and T is temperature in Kelvin.

We are given the volume (2.4 L) and temperature (300 K), and we just calculated the number of moles (0.826 mol). Plugging these values into the ideal gas law:

P × 2.4 L = 0.826 mol × 0.0821 L·atm/K·mol × 300 K

P = (0.826 mol × 0.0821 L·atm/K·mol × 300 K) / 2.4 L

P = 8.35 atm

Therefore, the pressure of hydrogen gas is 8.35 atm.