Explain why on addition of 1 mol of NaCl to 1 litre of water, the boiling point of water increases, while addition of 1 mol of methyl alcohol to one litre of water decreases its boiling point.
Sodium Chloride (NaCl) is a non-volatile solute, therefore, addition of NaCl to water lowers the vapour pressure of water. As a result, boiling point of water increases. Methyl alcohol on the other hand is more volatile than water, hence, its addition increases, the total vapour pressure over the solution and a decrease in boiling point of water results.
Calculate the molality of ethanol solution in which the mole fraction of water is 0.88.
Explain the solubility rule “like dissolves like” in terms of intermolecular forces that exist in solutions.
What type of intermolecular attractive interaction exists in the pair of methanol and acetone ?
What are colligative properties? Write the colligative property which is used to find the molecular mass of macromolecules.
State Henry’s law. What is the effect of temperature on the solubility of a gas in a liquid ?
Define azeotropes. What type of azeotrope is formed by positive deviation from Raoult’s law ?
Give an example.
The partial pressure of ethane over a saturated solution containing 6.56 × 10⁻² g of ethane is 1 bar. If the solution were to contain 5.0 × 10⁻² g of ethane, then what will be the partial pressure of the gas ?
State Raoult’s law for the solution containing volatile components. What is the similarity between Raoult’s law and Henry’s law ?
In the following ions:
Mn³⁺, V³⁺, Cr³⁺, Ti⁴⁺
(Atomic no: Mn = 25, V = 23, Cr = 24, Ti = 22)
(a) Which ion is most stable in an aqueous solution?
(b) Which ion is the strongest oxidizing agent?
(c) Which ion is colourless?
(d) Which ion has the highest number of unpaired electrons?
State Henry’s law. What is the effect of temperature on the solubility of a gas in a liquid ?
Following reactions can occur at cathode during the electrolysis of aqueous silver nitrate solution using Pt electrodes: