Thermodynamics
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Question : 1
Total: 10
A geyser heats water flowing at the rate of 3.0 litres per minute from 27°C to 77°C. If the geyser operates on a gas burner, what is the rate of consumption of the fuel if its heat of combustion is 4.0 × 104 J g – 1 ?
Solution:
Here, mass of water heated, m = 3000 g m i n − 1
Volume of water heated= 3.0 − 1
Rise in temperatureΔ T = ( 77 − 27 ) ° C = 50 ° C
Specific heat of waterc = 4.2 J g − 1 K − 1
Amount of heat usedΔ Q = m c Δ T
Now,
=
c Δ T
⇒
=
× 4.2 × 50 ;
= 63000 J min − 1
Heat of consumption( Δ Q ) = Δ m L
=
. L
⇒ 630000 J m i n − 1
= (
) × 4 × 10 4 J g − 1
Rate of consumption of fuel
=
= 15.75 ≈ 16 g min − 1
Volume of water heated
Rise in temperature
Specific heat of water
Amount of heat used
Now,
Heat of consumption
Rate of consumption of fuel
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