How does sprinkling of salt help in clearing the snow covered roads in hilly areas? Explain the phenomenon involved in the process.
When salt is spread over snow covered roads, snow starts melting from the surface because depression of freezing point of water takes place due to addition of salt. It helps in clearing of roads.
Hence, the phenomena is depression in freezing point which helps in clearing the snow covered roads in hilly areas.
What is "semipermeable membrane"?
Continuous sheets or films (natural or synthetic) which contain a network of submicroscopic holes or pores through which small solvent molecules (water etc.) can pass, but solute molecules of bigger size cannot pass are called semipermeable membrane. e.g., cellophane membrane.
Give an example of a material used for making semipermeable membrane for carrying out reverse osmosis.
Since pressure required for the reverse osmosis is very high, so, a suitable material is used for making semipermeable membrane. It is generally cellulose acetate placed over suitable support.
Match the items given in Column I and Column II.
| Column I | Column II | ||
|---|---|---|---|
| A. | Saturated solution | 1. | Solution having same osmotic pressure at a given temperature as that of given solution. |
| B. | Binary solution | 2. | A solution whose osmotic pressure is less than that of another. |
| C. | Isotonic solution | 3. | Solution with two components. |
| D. | Hypotonic solution | 4. | A solution which contains maximum amount of solute that can be dissolved in a given amount of solvent at a given temperature. |
| E. | Solid solution | 5. | A solution whose osmotic pressure is more than that of another. |
| F. | Hypertonic solution | 6. | A solution in solid phase. |
A. $\rightarrow$ (4) B. $\rightarrow(3)$ C. $\rightarrow$ (1) D. $\rightarrow$ (2) E. $\rightarrow(6) \quad$ F. $\rightarrow(5)$
A. Saturated solution A solution which contains maximum amounts of solute that can be dissolved in a given amount of solvent at a given temperature.
B. Binary solution A solution with two components is known as binary solution.
C. Isotonic solution A solution having same osmotic pressure at a given temperature as that of given solution is known as isotonic solution.
D. Hypotonic solution A solution whose osmotic pressure is less than another is known as hypotonic solution.
E. Solid solution A solution in solid phase is known as solid solution.
F. Hypertonic solution A solution whose osmotic pressure is greater than that of another is known as hypertonic solution.
Match the items given in Column I with the type of solutions given in Column II.
| Column I | Column II | ||
|---|---|---|---|
| A. | Soda water | 1. | A solution of gas in solid |
| B. | Sugar solution | 2. | A solution of gas in gas |
| C. | German silver | 3. | A solution of solid in liquid |
| D. | Air | 4. | A solution of solid in solid |
| E. | Hydrogen gas in palladium | 5. | A solution of gas in liquid |
| 6. | A solution of liquid in solid. |
A. $\rightarrow$ (5) B. $\rightarrow$ (3) C. $\rightarrow(4)$ D. $\rightarrow(2)$ E. $\rightarrow$ (1)
A. Soda water A solution of gas in liquid. e.g., $\mathrm{CO}_2$ in soft drinks.
B. Sugar solution A solution of solid in liquid in which sugar particles (soild) are dissolved in water (liquid).
C. German silver German silver is an alloy which is a solid solution of solid in solid. It is an alloy of $\mathrm{Cu}, \mathrm{Zn}$ and Ni .
D. Air A solution of gas in gas. Air is a mixture of various gases.
E. Hydrogen gas in palladium is an example of solution of gas in solid. This is used as an reducing agent.