a student has 100ml of 0.1M kcl solution to make it 0.2M, he has to
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To increase the concentration of a solution, we must increase the amount of solute even as the volume of the solution remains constant.
Moles in 100ml of 0.1 Molar Potassium Chloride is :
(100/1000) × 0.1 = 0.01 Moles.
Moles in 100ml of 0.2 Molar Potassium Chloride is
(1000/1000) × 0.2 = 0.02 moles
The difference in moles is :
0.02 - 0.01 = 0.01 moles
This is the amount of solute that should be added to raise the concentration to 0.2 M
Getting it in mass :
Molar mass of Potassium Chloride is :
74.55g /mol
Mass of solute is thus :
74.55 × 0.01 = 0.7455 g
We should therefore add 0.7455 g of potassium Chloride to raise the concentration to 0.2Molar
Moles in 100ml of 0.1 Molar Potassium Chloride is :
(100/1000) × 0.1 = 0.01 Moles.
Moles in 100ml of 0.2 Molar Potassium Chloride is
(1000/1000) × 0.2 = 0.02 moles
The difference in moles is :
0.02 - 0.01 = 0.01 moles
This is the amount of solute that should be added to raise the concentration to 0.2 M
Getting it in mass :
Molar mass of Potassium Chloride is :
74.55g /mol
Mass of solute is thus :
74.55 × 0.01 = 0.7455 g
We should therefore add 0.7455 g of potassium Chloride to raise the concentration to 0.2Molar
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