Question

Given the unbalanced chemical equation below, how many grams of Hydrogen gas will be produced if you react 20.5 grams of Zinc with excess hydrochloric acid. Report your answer rounded to the hundredth place. __Zn + __ HCl --> __ H2 + __ ZnCl2

Answer 1

0.63grams

Explanations

The balanced reaction between Zinc and hydrochloric acid is given as:

`Zn+2HCl\rightarrow H_2+ZnCl_2`

Given the following parameters

Mass of Zinc = 20.5 grams

Determine the moles of zinc

`\begin{gathered} mole\text{ of Zn}=\frac{mass}{molar\text{ mass}} \\ mole\text{ of Zn}=(20.5)/(65.38) \\ mole\text{ of Zn}=0.314moles \end{gathered}`

According to stoichiometry 1 mole of Zinc produces 1 mole of hydrogen gas.The moles of hydrogen that was produced will be 0.314moles

Determine the mass of hydrogen gas

`\begin{gathered} Mass\text{ of H}_2=mole* molar\text{ mass} \\ Mass\text{ of H}_2=0.314*2.016 \\ Mass\text{ of H}_2\approx0.63grams \end{gathered}`

Hence the mass of hydrogen gas that will be produced is 0.63grams