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

Question

The freezing point of a diluted milk sample is found to be -0.2°C, while it should have been -0.5°C for pure milk. How much water has been added to pure milk to make the diluted sample ? (A) 2 cups of water to 3 cups of pure milk (B) 1 cup of water to 3 cups of pure milk (C) 3 cups of water to 2 cups of pure milk (D) 1 cup of water to 2 cups of pure milk

Tardigrade Admin · Accepted Answer

Freezing point of milk =-0.5° C ∵ Δ T f =0.5° C Freezing point of diluted milk =-0.2° C ∴ Δ T f =0.2° C ((Δ Tt)1/(Δ Tt)1)=(0.5/0.2)=(kt m/kt m) Both has same amount of solute. Let y mole of solute (0.5/0.2)=(y × w2/w1 × y) ⇒ (w2/w1)=(5/2) w2=(5/2) w1

Q. The freezing point of a diluted milk sample is found to be −0.2∘C, while it should have been −0.5∘C for pure milk. How much water has been added to pure milk to make the diluted sample ?

2 cups of water to 3 cups of pure milk

1 cup of water to 3 cups of pure milk

3 cups of water to 2 cups of pure milk

1 cup of water to 2 cups of pure milk

Freezing point of milk =−0.5∘C ∵ΔTf​=0.5∘C Freezing point of diluted milk =−0.2∘C ∴ΔTf​=0.2∘C (ΔTt​)1​(ΔTt​)1​​=0.20.5​=kt​mkt​m​ Both has same amount of solute. Let y mole of solute 0.20.5​=w1​×yy×w2​​ ⇒w1​w2​​=25​ w2​=25​w1​

Q. The freezing point of a diluted milk sample is found to be $- 0. 2^{\circ} C$ , while it should have been $- 0. 5^{\circ} C$ for pure milk. How much water has been added to pure milk to make the diluted sample ?