Determine the volume of hydrogen gas needed to react completely with 6.00 L of oxygen gas to form water. (20pts)2H2(g) + O2(g) ⇨ 2H2O(g) at STP

Respuesta :

Explanation

Given

2H2(g) + O2(g) ⇨ 2H2O(g)

Volume = 6.00 L

At STP: Temperature = 273K

Pressure = 1 atm

We know that R constant = 0.0821 L.atm/mol.K

Solution

Step 1: Calculate the number of moles of oxygen at STP

Use the ideal gas law equation:

PV = nRT where P is the pressure, V is the volume, n is the number of moles, R is the gas constant and T is the temperature.

n = PV/RT

n = (1 atm x 6.00 L)/(0.0821 L.atm/mol.K x 273 K)

n = 0.27 mol

Step 2: Use the stoichiometry to find the moles of H2

The molar ratio between oxygen and hydrogen is 1:2

Therefore the moles of H2 = 0.27 x (2/1) = 0.535 mol

Step 3: Calculate the volume of H2

V = nRT/P

V = (0.535 mol x 0.0821 L.atm/mol.K x 273 K)/1 atm

V = 12.0 L

Answer

Volume of hydrogen = 12.0 L