## Question

A geyser, operating on LPG (liquefied petroleum gas) heats water flowing at the rate of 3.0 litres per minute, from 27^{o}C to 77^{o}C. If the heat of combustion of LPG is , how much fuel in grams is consumed per minute?

### Solution

15.75

Volume of water flowing per minute = 3.0 litres min ^{– 1}

= 3000 cm^{3} min^{ – 1}

Density of water = 1 g cm^{ – 3}

Rise in temperature = 77 – 27 = 50^{o}C

Specific heat of water = 4200 J

Now, heat of combustion of LPG

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