Single Choice

An ideal gas does work on its surroundings when it expands by 2.5 L against external pressure 2 atm. This work done is used to heat up 1 mole of water at 293 K. What would be the final temperature of water in Kelvin if specific heat for water is 4.184 $$Jg^{-1} K^{-1}$$?

A300
Correct Answer
B600
C200
D1000

Solution

Work done, $$w = -P_{ext.} dV$$ = -2 X 2.5 = -5 L atm = -506.3 J
Because this work is used in raising the temp of water, so work done is equal to the heat supplied i.e. $$w = q = m.C_s.\Delta T$$
Givent that, m=18 g (= 1 mole), $$C_s = 4.184 \ J \ g^{-1} K^{-1}$$
q = +506.3 J (Heat is given to water)
$$\therefore \Delta T = \frac{q}{C_s.m}=\frac{506.3}{4.184 \times 18} = 6.72$$
$$\therefore$$ Final temp, $$T_f = T_i + \Delta T$$ = 293 + 6.72 = 299.72 K $$\approx$$ 300 K

SIMILAR QUESTIONS

Chemical Thermodynamics

What will be the change in internal energy when $$12$$ $$kJ$$ of work is done on the system and $$2 \ kJ$$ of heat is given by the system?

Chemical Thermodynamics

$$W$$ is positive when the work is done on the system.

Chemical Thermodynamics

According to IUPAC conventions work done on the surroundings is:

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