Question # Chlorine is prepared in the laboratory by treating manganese dioxide ( left(mathrm{Mn} mathrm{O}_{2}right) ) with aqueous hydrochloric acid according to the reaction ( 4 mathrm{HCl}(mathrm{aq})+mathrm{MnO}_{2}(mathrm{s}) rightarrow 2 mathrm{H}_{2} mathrm{O}(ell)+mathrm{MnCl}_{2}(mathrm{aq})+mathrm{Cl}_{2}(mathrm{g}) ) How many grams of HCl react with ( 5.0 mathrm{g} ) of manganese dioxide?

# Chlorine is prepared in the laboratory by treating manganese dioxide ( left(mathrm{Mn} mathrm{O}_{2}right) ) with aqueous hydrochloric acid according to the reaction ( 4 mathrm{HCl}(mathrm{aq})+mathrm{MnO}_{2}(mathrm{s}) rightarrow 2 mathrm{H}_{2} mathrm{O}(ell)+mathrm{MnCl}_{2}(mathrm{aq})+mathrm{Cl}_{2}(mathrm{g}) ) How many grams of HCl react with ( 5.0 mathrm{g} ) of manganese dioxide?

(A) ( 8.4 mathrm{g} )

(B) ( 2.4 mathrm{g} )

(C) ( 1.4 mathrm{g} )

(D) ( 6.4 mathrm{g} )

Solution

( HC1 )

Molar Mans ( =36.5 mathrm{g} ).

( mathrm{MnO}_{2} )

Molar Mars = 87

( 5 g M n O_{2}=frac{5}{87} m o l )

require Ha = (4 times frac{5}{87})mol

(frac{20}{87} times 36.5g)

= 8.4g Ans (A)