5.00 g zinc added to hudroclric acid what is the mass of hydrogen gas

0.15g

Explanation:

Given parameters:

Mass of Zn  = 5g

Unknown:

Mass of hydrogen gas = ?

Solution:

To solve this problem, we must first write the reaction expression;

                 Zn + 2HCl →  ZnCl₂  + H₂

Now find the number of moles of the known specie which is Zn;

  Number of moles of Zn  =

    Molar mass of Zn  = 65.4g/mol

 Number of moles of Zn  =   = 0.08mole

    1 mole of Zn will produce 1 mole of H₂

    0.08 mole of Zn will give 0.08 mole of H₂

Mass of H₂ = number of moles x molar mass

   molar mass of H₂  = 2(1) = 2g/mol

   Mass of H₂  = 0.08mol x 2g/mol  = 0.15g