Answer to Question #131454 in General Chemistry for irdina

Question

a solution containing 121.8g of Zn(NO2)2 per liter has a density of 1.107 gmL^-1. calculate its molal concentration.

Answer 1

Molal concentration of solution is 0.875 mol/kg

C_m =moles of solute/kg of solvent

V(solute)=121.8 g/1.107g/mL^-1=116.35mL

V(solvent)= 1000mL-116.35mL=883.65 mL=0.88L=0.88 kg

n=m/M=121.8g/157.4g/mol=0.77 mol

C_m=0.77 mol/0.88 kg=0.875 mol/kg