Determine the amount of urea (NH2CONH2) to be added in 1000 g of water to decrease its vapour presssure by 25%.
Given: Molar mass of N. C. O and H are 14. 12. 16 and 1 2 mol-1 respectively.
Given: Molar mass of N. C. O and H are 14. 12. 16 and 1 2 mol-1 respectively.
Solution and Explanation
The correct answer is : 1111
\(\frac{P^0-P_s}{P_s}=\frac{n_{solute}}{n_{solvent}}\)
\(=\frac{\frac{x}{60}}{\frac{1000}{18}}=\frac{P^0-0.75P^0}{0.75P^0}\)
\(⇒x=\frac{10000}{9}=1111\ \text{gm}\)
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Concepts Used:
Solutions
A solution is a homogeneous mixture of two or more components in which the particle size is smaller than 1 nm.
For example, salt and sugar is a good illustration of a solution. A solution can be categorized into several components.
Types of Solutions:
The solutions can be classified into three types:
- Solid Solutions - In these solutions, the solvent is in a Solid-state.
- Liquid Solutions- In these solutions, the solvent is in a Liquid state.
- Gaseous Solutions - In these solutions, the solvent is in a Gaseous state.
On the basis of the amount of solute dissolved in a solvent, solutions are divided into the following types:
- Unsaturated Solution- A solution in which more solute can be dissolved without raising the temperature of the solution is known as an unsaturated solution.
- Saturated Solution- A solution in which no solute can be dissolved after reaching a certain amount of temperature is known as an unsaturated saturated solution.
- Supersaturated Solution- A solution that contains more solute than the maximum amount at a certain temperature is known as a supersaturated solution.