Question

Which of the following when mixed would raise the temperature of 20gm of water at 30°C most?
(a) 20 gm of water at 40°C
(b) 40 gm of water at 35°C
(c) 10 gm of water at 50°C
(d) 4 gm of water at 80°C



please can anyone do this problem step by step ( urgent)​

Answer 1

Initial temperature of the given 20g water is not given so let it is x heat taken by this water to go 300C=20×1×(30−x)=20(30−x)calsame heat should be given by another water to reach to this temparature .suppose it is option (a) then heat given by it =20×1×10=200calbut here missing of information due to which we can not say exact option .

Answer 2

Answer:

answer (d) which gives 38.3°C

Explanation:

(a) 20 gm of water at 40°C  

20x30 + 20x40 = 40ΔT , ΔT = 35°C

(b) 40 gm of water at 35°C

20x30 + 40x35 = 60ΔT , ΔT = 33.3°C

(c) 10 gm of water at 50°C

20x30 + 10x50 = 30ΔT , ΔT = 36.6°C

(d) 4 gm of water at 80°C

20x30 + 4x80 = 24ΔT , ΔT = 38.3°C

→ choose answer (d) which gives 38.3°C