Question

What mass of $Mg(OH{)}_2$ is required to neutralise 125 ml of 0.136 M hydrochloric acid solution ?Molar mass of$Mg(OH{)}_2$ = 58.33 g $mo{l}^{-1}$

• A. 0.248 g
• B. 0.496 g
• C. 0.992 g
• D. 1.98 g

Answer 1

The correct option is B

0.496 g

$Mg(OH{)}_2+2HCl\to MgC{l}_2+2H_{2}O125mL\times 0.136M=17\times {10}^{-3}molesofHCL=17\times {10}^{-3}\times 36.5=0.6205gofHCl.58.33gofMg(OH{)}_{2}requires2\times 36.5gofHCl?0.6205gofHCl=\frac{0.6205\times 58.33}{2\times 36.5}=0.496gm$