Question

A solution of KMnO4 was found by titration to be 0.05436 M at 24°C. what was the molarity when the temperature dropped to 14°C?

Answer 1

Molarity = mol / L

the temperature change affects the volume of solutoin

at 24°C

M = 0.05436 mol per liter

assume there is

0.05436 mol

the 1 L

will be affected when T = 14°C

the change of volume:

@T = 24°C D = 0.99727995 g/ml

@T = 14°C D = 0.99924740 g/ml

find the mass of solvent:

D = mass/V

V = 1 L so

mass = D*V = 997.27995*1 = 997.27995 g (in 1 liter)

for 14°C

then

997.27995 g will turn to

D = mass/V

V = mass/D = 997.27995 /0.99924740 = 998.031068182 ml = 0.998031068182 L

M = mol /L

M = 0.05436 /0.998031068182 = 0.05446724228 M