Question

To prepare 100 cm³ of NaCl solution with a concentration of 2 mol/dm³ Ar(Na)=23; Ar(Cl)=35.5 are needed?

Answer 1

Moles of NaCl$=2×\frac{100}{1000}=0.2moles$

$2Na(s) + Cl _2 ( g ) → 2NaCl(s)$

Hence moles of $Na=0.2$ and $Cl=0.1$