The temperatures of equal masses of three different liquids A, B and C are 12°C, 19°C and 28°C respectively. The temperature when A and B are mixed is 16°C, and when B and C are mixed, it is 23°C. What will be the temperature when A and C are mixed ?

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1 Answers

The temp. of A = 12°C 

The temp. of B = 19°C

The temp. of C = 28°C 

The temp of => A + B = 16°

The temp. of => B + C = 23°

In accordance with the principle of caloriemetry when A & B are mixed

MCA (16 – 12) = MCB (19 – 16) => CA4 = CB3 => CA = 3/4CB …(1)

And when B & C are mixed

MCB (23 – 19) = MCC (28 – 23) => 4CB = 5CC => CC = 4/5CB …(2)

When A & c are mixed, if T is the common temperature of mixture
MCA(T – 12) = MCC(28 – T)

=> (3/4)CB(T - 12) = (4/5)CB(28 - T)

=> 15T - 180 = 448 - 16T

=> T = 625/31 = 20.258°C = 20.3°C

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