Question

In the reaction Mg (s) + 2HCl (aq) H2 (g) + MgCl2 (aq), how many moles of hydrogen gas will be produced from 75.0 milliliters of a 1.0 M HCl in an excess of Mg? 0.75 moles 1.0 moles 0.038 moles 0.075 moles

Answer 1

The answer is .038 because it rounded from .0375 to .038

Answer 2

Here amount of HCl can be calculated as:

As concentration of HCl= 1 M or 1 mol L

Volume of HCl= 75mL=0.075L

So number of moles of HCl will be= 0.075\times 1

number of moles of HCl will be= 0.075 mol

As we see from the equation,

Mg (s) + 2HCl (aq)------->H₂ (g) + MgCl₂ (aq)

That 2 moles of HCl will produce 1 mole of H₂

So 0.075 mol of HCl will produce 0.038 mole of H₂