#Zn(s) + 2HCl(aq) - H_2 (g) + ZnCl_2(aq) + #heat energy.
If 30.0 g of #Zn# react, how many grams of #H_2# will form?

Question

#Zn(s) + 2HCl(aq) -> H_2 (g) + ZnCl_2(aq) + #heat energy.  
If 30.0 g of #Zn# react, how many grams of #H_2# will form?

Luna Chen · Accepted Answer

1.85 g of hydrogen will form.

1. Write the equation that is balanced. #"Zn" + "2HCl" → "ZnCl"_2 + "H"_2# 2. Calculate the moles of #"Zn"#. #"Moles of Zn" = 30.0 color(red)(cancel(color(black)("g Zn"))) × ("1 mol Zn")/(65.38 color(red)(cancel(color(black)("g Zn")))) = "0.4589 mol Zn"# 3. Calculate the moles of #"H"_2#. #"Moles of H"_2 = 0.4589 color(red)(cancel(color(black)("mol Zn"))) × ("2 mol H"_2)/(1 color(red)(cancel(color(black)("mol Zn")))) = "0.9177 mol H"_2# 4. Calculate the mass of #"H"_2#. #"Mass of H"_2 = 0.9177 color(red)(cancel(color(black)("mol H"_2))) × ("2.016 g H"_2)/(1 color(red)(cancel(color(black)("mol H"_2)))) = "1.85 g H"_2#

Cooper Adams · Answer

undefined Using the balanced equation:

1 mole of Zn produces 1 mole of H2.

The molar mass of Zn is 65.38 g/mol.

So, for 30.0 g of Zn:

30.0 g Zn * (1 mol Zn / 65.38 g Zn) * (1 mol H2 / 1 mol Zn) = 0.459 moles of H2

Now, to find the mass of H2:

0.459 moles H2 * (2.02 g H2 / 1 mol H2) = 0.927 g H2

#Zn(s) + 2HCl(aq) -&gt; H_2 (g) + ZnCl_2(aq) + #heat energy. If 30.0 g of #Zn# react, how many grams of #H_2# will form?

#Zn(s) + 2HCl(aq) -> H_2 (g) + ZnCl_2(aq) + #heat energy. If 30.0 g of #Zn# react, how many grams of #H_2# will form?