Answer to Question #103411 in General Chemistry for Marissa

Question

Calculate the number of moles in 112.7 g of each of the following compounds.
SO2
Na2SO4
BaSO4
KAI(SO4)2

Answer 1

Number of moles$(N)=\frac{M_g}{M_a}$ where $M_g$ is the given mass of compound and $M_a$ is the molar mass of compound.

In the given question,$M_g=112.7 \ g$ same for all compounds.

$SO_2:$

$M_a=32+2\times 16=64\ g$

$N=\frac{112.7}{64}=1.76$

$Na_2SO_4:$

$M_a=23\times 2+32+16\times 4=142\ g$

$N=\frac{112.7}{142}=0.794$

$BaSO_4:$

$M_a=137+32+16\times 4=233\ g$

$N=\frac{112.7}{233}=0.484$

$KAl(SO_4)_2:$

$M_a=39+27+2\times(32+16\times 4)=258\ g$

$N=\frac{112.7}{258}=0.437$