When 2.4 g zinc is added to hydrochloric acid, 450 ml of hydrogen gas form at a temperature of 32 C what is the pressure of the gas

First we need to find the number of moles of hydrogen gas formed

Zn + 2HCl - - - > ZnCl₂ + H₂

stoichiometry of Zn to H₂ is 1:1

the number of Zn moles reacted - 2.4 g / 65.4 g/mol = 0.0367 mol

assuming Zn to be the limiting reactant

number of Zn moles reacted = number of H₂ moles formed

therefore number of H₂ moles formed = 0.0367 mol

we can use ideal gas law equation to find the pressure

PV = nRT

P - pressure

V - Volume - 450 x 10⁻⁶ m³

n - number of moles - 0.0367 mol

R - universal gas constant - 8.314 Jmol⁻¹K⁻¹

T - temperature - 32 °C + 273 = 305 K

substituting these values in the equation

P x 450 x 10⁻⁶ m³ = 0.0367 mol x 8.314 Jmol⁻¹K⁻¹ x 305 K

P = 206.8 kPa

pressure is 206.8 kPa