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# Confused! kindly explain, - The freezing point of a diluted milk sample is found to be , while it should have beenfor pure mi - Solutions - JEE Main

The freezing point of a diluted milk sample is found to be $-0.2^{0}C$ , while it should have been $-0.5^{0}C$ for pure milk. How much water has been added  to pure milk  to make the diluted sample ?

• Option 1)

2 cups of water to 3 cups of pure milk.

• Option 2)

3 cups of water to 2 cups of pure milk.

• Option 3)

1 cup of water to 3 cups of pure milk.

• Option 4)

1 cup of water to 2 cups of pure milk.

Views

Depression in freezing point -

-

Freezing -

Freezing  occurs when liquid solvent is in equilibrium with solid solvent. As non volatile solute decreases, the vapour pressure freezing point decreases.

-As we knoew that

Freezing point of milk $= -0.5^{0}C\because \Delta T_{f}= 0.5^{0}C$

Freezing point of milk (diluted)$=-0.2^{0}C \because \Delta T_{f}= 0.2^{0}C$

$\frac{\left ( \Delta T_{f} \right )i}{\left ( \Delta T_{f} \right )ii}= \frac{0.5}{0.2}= \frac{K_{f}m}{K_{f}m}= \frac{x\left ( mole \right )\times weight\left ( 2 \right )}{weight_{\left ( 1 \right )\times }x\left ( mole \right )}$

$W_{2}= \frac{5}{2}W_{1}$

Option 1)

2 cups of water to 3 cups of pure milk.

Option 2)

3 cups of water to 2 cups of pure milk.

Option 3)

1 cup of water to 3 cups of pure milk.

Option 4)

1 cup of water to 2 cups of pure milk.

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