How many milliliters of calcium, with a density of 1.55 g/mL, are needed to produce 12.4 grams of hydrogen gas in the single replacement reaction below? Be sure to show the work that you did to solve this problem.

Unbalanced equation: Ca + HF CaF2 + H2

Question

How many milliliters of calcium, with a density of 1.55 g/mL, are needed to produce 12.4 grams of hydrogen gas in the single replacement reaction below? Be sure to show the work that you did to solve this problem. 

Unbalanced equation: Ca + HF   CaF2 + H2

anonymous · Answer

1. Balance the equation: Ca + 2 HF yields CaF2 + H2
2.
? mL Ca
Ca density 1.55 g/mL
12.4 g H2
3. Problem
12.4 g H2 * 1 mol H2 * 1 mol Ca * 40.078 g Ca * 1 mL Ca = 159.055 mL Ca
               2.0158 g H2   1 mol H2     1 mol Ca  1 .55 g Ca
The answer is you would need 159.055 mL of Ca.

anonymous · Answer

No.. This is not a practice exam. This is a module quiz from FLVS and it's cheating if you use this answer. Plus it has a obvious mistake in it. 
Mr. Carlyle 
FLVS Chemistry Instructor 

This question is a violation of the OpenStudy Guidelines. The question is from an online school plus a violation by solicitation for members to unknowingly assist them cheating on an exam. 30653065chem30653065