Question

Consider Zn + 2HCl → ZnCl2 + H2 (g). If 0.30 mol Zn reacts with HCl, how many grams of HCl are needed?

Answer 1

Answer:

22 grams

Explanation:

Zn + 2HCl → ZnCl2 + H2

The first step to answering this question is to calculate the amount of moles of HCl needed. We do this by multiplying the coefficient of HCl in the equation over the coefficient of Zn.

0.30mol × $\frac{2}{1}$ = 0.60 mol HCl

Now, to figure out how many grams we must multiply the amount of moles of HCl by it's molar mass. This molar mass can be found by adding the molar masses of all the elements in HCl.

0.60mol × 36.46 g/mol = 21.87g

Using proper sig figs, 22 grams of HCl are required for this reaction.