1 What is the molarity M of particles in each of the followi

1. What is the molarity (M) of particles in each of the following solutions? a. 1.0 M K2SO4 b. 1.5 M Mg(NO3)2 c. 0.0333 M CH3CH2OH d. 0.944 M HC e. 0.100 M (NH4)3PO.4

Solution

1.

(a) 1.0 M K2SO4

K₂SO₄    <------>   2K⁺   +   SO₄^-2

So,
K⁺ = 2 x 1.0 M = 2.0 M
SO₄^-2 = 1 x 1.0 M = 1.0 M

(b) 1.5 M Mg(NO3)2

Mg(NO₃)₂    <------>   Mg²⁺   +   2NO₃^-

So,

Mg²⁺ = 1 x 1.5 M = 1.5 M
NO₃^- = 2 x 1.5 M = 3.0 M

(c) 0.0333 M CH₃CH₂OH

CH₃CH₂OH don’t dissociate into ions

(d) 0.944 M HCl

HCl    <------>   H⁺   +   Cl^-

So,

H⁺ = 1 x 0.944 M = 0.944 M
Cl^- = 1 x 0.944 M = 0.944 M

(e) 0.100 M (NH4)3PO4

(NH₄)₃PO₄    <------>   3NH₄⁺   +   PO₄^3-

So,

NH₄⁺ = 3 x 0.100 M = 0.300 M
PO₄^3- = 1 x 0.100 M = 0.100 M