An athelete in a gymansium room lifts a `50 kg` mass through a vertical distance of `2.0 m , g=9.8 ms^(-2)`. The mass is allowed to fall through `2.0` m distance while coupled to an electrical generator. The electrical generator produces an equal amount of electrical work. this electrical work is used to produce aluminium by hall's process involving the change, `Al_(2)O_(3)("molten")+3C_((s))to2Al_((l))+3CO_((g))`
The reaction require standard free energy change equal to `593 k J`. how many times must the athelete lift `50 kg` mass and to drop and couple with generator to produce sufficient Gibbs free energy to produce `27 g Al?`

Options

A. 325
B. 315
C. 303
D. 325

Answer

C

Explanation

`DeltaG^(@)` needed for `54g Al =593kJ`
`:.DeltaG^(@)` needed for `27gAl=593/2kJ`
Heat produced when 50 kg mass falls from 2m in Q,
then `Q=mgh=50xx9.8xx2=980J`
Thus number of lilfting and fall
`n=(DeltaG^(@))/Q=(593xx10^(#))/(2xx980)=302.6=303`
Thus, athlete should go for 303 lifting.