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Calculate heat of combustion of coal, when 0.5kg of coal on burning raise the temperature of 50 liters of water from `20^(@)C` to `90^(@)C` |
Answer» Here, mass of coal, `M = 0.5 kg`, mass of water `m = (50 xx 1000) c c xx 1 g//c c` `=50 xx 10^(3) g` `Delta T = 90^(@) - 20^(@) = 70^(@)C` Specific heat of water `s=10^(3) cal. Kg^(-1) .^(@)C^(-1)` Total heat produced = `ms Delta T` `(50 xx 10^(3)) xx 1 xx 70 cal. = 35 xx 10^(5) cal`, Heat of combustion of coal `(35 xx 10^(5))/(M) = (35 xx 10^(5))/(0.5) = 7 xx 10^(6) cal, kg^(-1)`. |
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