Question

1. based on the provided data, which of the following amounts of magnesium and hydrochloric acid is most likely to produce between 100 and 300 ml of gas? a. 1.0 g mg and 90 ml hcl b. 0.5 g mg and 90 ml hcl c. 0.5 g mg and 30 ml hcl d. 0.5 g mg and 10 ml hcl

Explanation:

Step1: Analyze data trends

From trials 1-5: 0.5g Mg with 2→15→50→75→100 mL HCl gives balloon volumes 33.3→98.9→319.3→319.3→319.3 mL. So 50+ mL HCl fully reacts 0.5g Mg to make ~319.3 mL gas.

Step2: Target gas range

We need 100-300 mL gas, so use less than full HCl for 0.5g Mg, or adjust Mg amount.

Step3: Evaluate options

• A: 1.0g Mg needs more HCl than 100 mL to fully react, gas would exceed 319.3×2=638.6 mL, too much.
• B: 0.5g Mg with 90 mL HCl: 90 mL ≥50 mL, so full reaction gives ~319.3 mL, over 300 mL.
• C: 0.5g Mg with 30 mL HCl: 30 mL <50 mL, so HCl is limiting. Gas volume is proportional to HCl: $\frac{30}{50} \times 319.3 = 191.6$ mL, which is 100-300 mL.
• D: 0.5g Mg with 10 mL HCl: $\frac{10}{50} \times 319.3 = 63.9$ mL, below 100 mL.

Answer:

C. 0.5 g Mg and 30 mL HCl