Resulting pressure is 13.6 atm.
Explanation:
Using Ideal gas equation, we can find the pressure of the gases formed in the reaction.
PV = nRT
Number of moles, n = given mass / molar mass = 20 g / 18 g/mol
= 1.11 moles
Volume, V = 2 L
Temperature, T = 25°C + 273 = 298 K
R = gas constant = 0.08206 L atm K⁻¹ mol⁻¹
P = nRT/V
= 1.11×0.08206 ×298 / 2
= 13.6 atm
