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When 1.2 g of Sulphur is melted with 15 ...

When 1.2 g of Sulphur is melted with 15 g of naphthalene, the solution freezes at`77.2^(@)C`. What is the molar mass of this form of Sulphur?
Deta for napthalene:
Melting point (f.pt.) ` 80.0^(@)C`
Freezing point depression constant `K_(f) 6.80Km^(-1)`

A

`180 g mol^(-1)`

B

`194 g mol^(-1)`

C

`260 g mol^(-1)`

D

`450 g mol^(-1)`

Text Solution

Verified by Experts

The correct Answer is:
B
`2.8 = (1.2)/(15 xx x) xx 10^(3) xx 6.8`
`x = 194`
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