The enthalpy of combustion of glucose is- `2808 kJmol^(-1)` at `25^(@)` C. How many grams of gluc

Answer

(a) 0.47 gm, (b) 0.47 kg

Explanation

Only `25%` energy used of for useful work
(i) Energy requried = mgh
`= 62. 5 xx 9.8 xx 3 = 1837.5 J`
gulcose requried `= (180)/(702 xx 10 ^(3))xx 1837.5 = 0.471 gram`
(ii) Energy requried = ` 62.5 xx 9.8 xx 3000 = 1837500 J = 0.471 gram `
Mass requried `=(180 xx 1837.5 )/(702) = 471 g = 0.47 kg`