Multiple Choice
What is the first step in solving a stoichiometric problem?
3. Chemical Reactions
Stoichiometry
Struggling with General Chemistry?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
What mass of Aluminum (Al) is needed to react completely with 35.0 mL of 2.0 M Hydrochloric acid (HCl), given the reaction: 2 Al + 6 HCl β 2 AlCl3 + 3 H2?
A
0.63 g
B
1.26 g
C
0.84 g
D
0.42 g
Verified step by step guidance1
Determine the number of moles of HCl present in the solution using the formula: \( \text{moles of HCl} = \text{Molarity} \times \text{Volume in Liters} \). Convert 35.0 mL to liters by dividing by 1000.
Use the stoichiometry of the balanced chemical equation \( 2 \text{Al} + 6 \text{HCl} \rightarrow 2 \text{AlCl}_3 + 3 \text{H}_2 \) to find the mole ratio between Al and HCl. From the equation, 2 moles of Al react with 6 moles of HCl.
Calculate the moles of Al needed using the mole ratio: \( \text{moles of Al} = \frac{2}{6} \times \text{moles of HCl} \).
Convert the moles of Al to mass using the molar mass of Aluminum. The molar mass of Al is approximately 26.98 g/mol. Use the formula: \( \text{mass of Al} = \text{moles of Al} \times \text{molar mass of Al} \).
Compare the calculated mass of Al with the given options to determine the correct answer.
Related Videos
Related Practice
