What volume of hydrogen gas,measured at STP,is produced in the reaction of excess aluminum with 50.0 mL of 0.935 M hydrochloric acid?
A)0.531 L
B)1.06 L
C)2.12 L
D)0.0474 L
E)0.0237 L

Question

Quizplus · Accepted Answer

The reaction between aluminum (Al) and hydrochloric acid (HCl) produces aluminum chloride (AlCl3) and hydrogen gas (H2). The balanced chemical equation is: $2Al + 6HCl \rightarrow 2AlCl3 + 3H2$.First, calculate the moles of HCl using the given concentration and volume:Moles of HCl = Molarity × Volume (in liters) = 0.935 mol/L × 0.0500 L = 0.04675 molFrom the balanced equation, 6 moles of HCl produce 3 moles of H2. Therefore, 0.04675 moles of HCl will produce:$0.04675 \, \text{mol HCl} \times \frac{3 \, \text{mol H2}}{6 \, \text{mol HCl}} = 0.023375 \, \text{mol H2}$At STP (Standard Temperature and Pressure), 1 mole of any gas occupies 22.4 liters. Thus, the volume of hydrogen gas produced is:Volume of H2 = 0.023375 mol × 22.4 L/mol = 0.5236 L, which rounds to 0.531 L.

What Volume of Hydrogen Gas,measured at STP,is Produced in the Reaction