Aluminum reacts with excess hydrochloric acid to form aqueous aluminum chloride and 190.6 ml of hydrogen gas (collected over water at 26°C and 0.89 atm). (Vapor pressure of water at 26ºC = 25.2 mmHg.) How many grams of aluminum reacted? Enter to 4 decimal places.

0.1296 grams of aluminum reacted

Explanation:

Equation of reaction:

2Al + 6HCl = 2AlCl3 + 3H2

From the ideal gas equation

PV = nRT

n = PV/RT

P = (25.2/760) atm + 0.89atm = 0.923 atm

V = 190.6 ml = 190.6cm^3

R = 82.057cm^3. atm/gmol. K

T = 26°C = 26+273K = 299K

n = 0.923*190.6/82.057*299 = 0.0072 moles of H2

From the equation of reaction

3 moles of hydrogen gas is formed from 2 moles of aluminum

Therefore, 0.0072 moles of hydrogen gas is formed from (0.0072*2/3 = 0.0048) moles of aluminum

Number of moles of aluminum that reacted = 0.0048 moles

Mass of aluminum that reacted = number of moles * MW = 0.0048 * 27 = 0.1296 grams