In an experiment to determine the specific heat of a metal,` a 0.20 kg` block of the mental at `150 .^(@) C` is dropped in a copper calorimeter (of water equivalent `0.025 kg` containing `150 cm^3` of water at `27 .^(@) C`. The final temperature is `40.^(@) C`. The specific heat of the metal is.

Options

A. `0.1 Jg^-1 .^(@) C^-1`.
B. `0.2 Jg^-1 .^(@) C^-1`.
C. `0.3 cal g^-1 .^(@) C^-1`.
D. `0.1 cal g^-1 .^(@) C^-1`.

Answer

D

Explanation

Heat lost = Heat gained
`0.20 xx 10^3 xx s(150 - 40)`
= `150 xx 1 xx (40 - 27) + 0.025 xx 10^3 xx (40 - 27)`
`{because s_(water) =1 cal g^-1(.^(@) C)^-1}`
`:. 22000 s = 1950 +325`
`:. 22000 s = 2275`
`:. s = 0.10 cal g^-1(.^(@) C)^-1`.