Given below are two statements : Statement (I) : NaCl is added to the ice at $0^{\circ} \mathrm{C}$, present…
Given below are two statements :
Statement (I) : NaCl is added to the ice at $0^{\circ} \mathrm{C}$, present in the ice cream box to prevent the melting of ice cream.
Statement (II) : On addition of NaCl to ice at $0^{\circ} \mathrm{C}$, there is a depression in freezing point.
In the light of the above statements, choose the correct answer from the options given below :
Both Statement I and Statement II are false
Statement I is false but Statement II is true
Statement I is true but Statement II is false
Both Statement I and Statement II are true
Solution
Statement (I) asserts that \(\text{NaCl}\) is added to ice at \(0^{\circ }\text{C}\) in an ice cream box to prevent the melting of ice cream. This statement is considered correct. The addition of \(\text{NaCl}\) to ice creates a freezing mixture, which achieves a lower temperature than \(0^{\circ }\text{C}\), thereby effectively keeping the ice cream frozen for a longer duration.
Statement (II) states that on addition of \(\text{NaCl}\) to ice at \(0^{\circ }\text{C}\), there is a depression in freezing point.
This statement is also considered correct. The phenomenon of freezing point depression is a colligative property, where the addition of a non-volatile solute like \(\text{NaCl}\) to a solvent (water from melting ice) lowers the freezing point of the solution below that of the pure solvent.
Relationship between Statements
Statement (II) provides the scientific principle that explains the effectiveness of the action described in Statement (I). The depression in freezing point caused by the addition of \(\text{NaCl}\) to ice is the reason why a lower temperature is achieved, which in turn helps in preventing the melting of ice cream. Therefore, Statement (II) is the correct explanation for Statement (I). Final Answer
Both Statement (I) and Statement (II) are true, and Statement (II) is the correct explanation of Statement (I).