1. Write short notes on;(a) Units to express concentration of solution(b) Henry’s law(c) Ideal solutions

Molarity (M)indicates the number of moles of solute per liter of solution (moles/Liter) and is one of the most common units used to measure the concentration of a solution.

Henry’s law is a gas law that states that the amount of gas that is dissolved in a liquid is directly proportional to the partial pressure of that gas above the liquid when the temperature is kept constant. The constant of proportionality for this relationship is called Henry’s law constant (usually denoted by ‘kH‘).
The mathematical formula ofHenry’s lawis given by:

P ∝ C (or) P = kH.C

0r X = kH.P

Where,

‘P’ denotes the partial pressure of the gas in the atmosphere above the liquid.
‘C’ denotes the concentration of the dissolved gas.
‘kH’ is Henry’s law constant of the gas.
X is a mole fraction of gas.

Ideal solutions are thesolutions in which solute solute and solventsolvent interactions are almost similar to solute solvent interactions(A – B = A – A or B – B interactions) and such solutions satisfy the following requirements: They obey Raoult's law for all ranges of concentrations and temperature.