Question

0.0665 g sample of aluminum metal reacts with hydrochloric acid to give 90.5 mL of hydrogen gas at 23 degree celcius and an atmospheric pressure of 756 mm Hg. The hydrogen gas is collected over water. Using stoichometry determine the theoretical yield of hydrogen gas in moles that will be produced by the complete reaction of aluminum metal.

a. 0.0102 moles
b. 0.201 moles
c. 0.301 moles
d. 0.402 moles

Answer 1

To determine the theoretical yield of hydrogen gas produced by the complete reaction of aluminum metal, we need to calculate the moles of aluminum used and use the stoichiometric ratio between aluminum and hydrogen gas.

Step-by-step explanation:

To determine the theoretical yield of hydrogen gas produced by the complete reaction of aluminum metal, we first need to calculate the moles of aluminum used. We can do this by converting the mass of the aluminum sample to moles using the molar mass of aluminum. The molar mass of aluminum is 26.98 g/mol.

Using the mass-to-moles conversion:

0.0665 g Al * (1 mol Al / 26.98 g Al) = 0.00246 mol Al

From the balanced equation for the reaction:

2 Al(s) + 6 HCl(aq) → 2 AlCl3(aq) + 3 H2(g)

Since the stoichiometric ratio between aluminum and hydrogen gas is 2:3, the moles of hydrogen gas produced will be:

0.00246 mol Al * (3 mol H2 / 2 mol Al) = 0.00369 mol H2

Therefore, the theoretical yield of hydrogen gas in moles that will be produced by the complete reaction of aluminum metal is approximately 0.00369 moles (option a. 0.0102 moles is incorrect).