Question

Calculate the molarity of the following solution. $30$ g of $Co(N{O}_3{)}_2\cdot 6H_{2}O$ in $4.3$L of solution.

Answer 1

Mass $=30g$

solution$=4.3L$

$moles=\frac{mass}{molarmass}$

Molar mass of $Co{\left(N{O}_3\right)}_2.6H_{2}O$

$=58.7+2\left(14+3\times 16\right)+6\left(2+16\right)=290.7g/mol$

$Molarity=\frac{moles}{solution}$

$=\frac{0.1032gm/mol}{4.3}$

$=0.024M$

$moles=\frac{30}{290.7}$

$=0.1032moles$