Properties Of Solids And Liquids Question 112
Question: The temperature of equal masses of three different liquids A, B and C are 12ºC, 19ºC and 28ºC respectively. The temperature when A and B are mixed is 16ºC and when B and C are mixed is 23ºC. The temperature when A and C are mixed is [Kerala PET 2005]
Options:
A) 18.2ºC
B) 22ºC
C) 20.2ºC
D) 25.2ºC
Show Answer
Answer:
Correct Answer: C
Solution:
Heat gain = heat lost CA(16 -12) = CB (19 - 16)
therefore $ \frac{C _{A}}{C _{B}} $ = $ \frac{3}{4} $ and CB(23 - 19) = CC (28 - 23)
therefore$ \frac{C _{B}}{C _{C}} $ = $ \frac{5}{4} $
therefore $ \frac{C _{A}}{C _{C}}=\frac{15}{16} $ …(i) If q is the temperature when A and C are mixed then, $ C _{A}(\theta -12) $ = $ C _{C}(28-\theta ) $
therefore $ \frac{C _{A}}{C _{C}} $
$ =\frac{28-\theta }{\theta -12} $ …(ii) On solving equation (i) and (ii) q = 20.2ºC.
