Respuesta :
The chemical reaction is given as:
[tex]Zn(s)+2HCl(aq)\rightarrow ZnCl_{2}(aq)+H_{2}(g)[/tex]
First, calculate the number of moles of zinc:
Number of moles = [tex]\frac{Given mass in g}{Molar mass}[/tex]
Given mass of zinc = [tex]14.0 g[/tex] and molar mass of zinc = [tex]65.4 g/mol[/tex]
Number of moles = [tex]\frac{14.0 g}{65.4 g/mol}[/tex]
= [tex]0.2140 moles[/tex]
Now, moles of hydrogen = [tex]number of moles of zinc\times \frac{1 mol of hydrogen}{1 mol of zinc}[/tex] ( as 1 mole of zinc gives 1 mole of hydrogen)
= [tex]0.2140\times \frac{1 mol of hydrogen}{1 mol of zinc}[/tex]
= [tex]0.2140 mol[/tex] of hydrogen.
Volume of hydrogen is calculated by:
[tex]PV=nRT[/tex]
where, P = pressure = 1 atm at STP
V = volume
n= number of moles
R = gas constant = [tex]0.082 Latm/Kmol[/tex]
T = temperature= 273 K at STP
Now, insert the values in formula, we get
[tex]V=\frac{nRT}{P}[/tex]
[tex]V=\frac{0.2140 mol\times 0.082 Latm/Kmol\times 273 K}{1 atm}[/tex]
[tex]V=\frac{0.2140 mol\times 0.082 Latm/Kmol\times 273 K}{1 atm}[/tex]
[tex]V=4.790 L\simeq 4.80 L[/tex]
Thus, volume of hydrogen is [tex]4.80 L[/tex] i.e. second option is the correct answer.
