NaH reacts with water to form H₂ gas and NaOH. What will the pressure be inside a closed 4.0 L container at 27 ° C if 20 g of NaH reacts with a stoichiometric amount of H₂O?

Question

Quizplus · Accepted Answer

The balanced equation for the reaction is:
2NaH + H2O → 2NaOH + H2S

First, we need to find the number of moles of NaH:
n(NaH) = m/M = 20g/23g/mol = 0.87 mol

Since the reaction is 2:1, the number of moles of H2S produced will be half of that:
n(H2S) = 0.5 x n(NaH) = 0.44 mol

Now we can use the ideal gas law to find the pressure of the H2S gas:
PV = nRT
P = nRT/V

We need to convert the temperature to Kelvin:
T = 27 + 273 = 300 K

Substituting the values:
P = (0.44 mol) (0.08206 L atm/K mol) (300 K) / 4.0 L
P = 5.14 atm

Therefore, the pressure inside the container will be 5.1 atm, which is the closest option.

NaH Reacts with Water to Form H2 Gas and NaOH

NaH Reacts with Water to Form H₂ Gas and NaOH