A scientist needs a refrigeration machine to maintain temperature of `-13^(@)C` for certain chemical process. How much work must be performed on the system during each cycle of its operation if `3000 J` of heat is to be withdrawn from the `-13^(@)C` reservoir and discharged to the room at `+27^(@)C`? Assume that the machine operates at `100 %` of its theoretical efficiency.A. `65000 J`B. `3000 J`C. `154 J`D. `133 J`

A scientist needs a refrigeration machine to maintain temperature of `

1.	A scientist needs a refrigeration machine to maintain temperature of `-13^(@)C` for certain chemical process. How much work must be performed on the system during each cycle of its operation if `3000 J` of heat is to be withdrawn from the `-13^(@)C` reservoir and discharged to the room at `+27^(@)C`? Assume that the machine operates at `100 %` of its theoretical efficiency.A. `65000 J`B. `3000 J`C. `154 J`D. `133 J`
Answer» Correct Answer - B `eta=(W)/(q_(2))`. Since `eta=1 :. W= q_(2)=3000J`.

Discussion

No Comment Found

Related InterviewSolutions

The number of state functions the following properties are Temperature, Pressure, Volume, Heat capacity. Density, `pH` of a solution, `EMF` of a cell. Entropy, Free energy. Enthalpy, Surface tension, Viscosity, Boiling point.
Enthalpy of reaction `DeltaH` is expressed asA. `DeltaH=sumH_(P)-sumH_(R )`B. `DeltaH=dH_(P)+dH_(R )`C. `DeltaH=(dH_(P))/(dH_(R ))`D. `DeltaH=(sumH_(P))/(sumH_(R ))`
Heat capacity isA. `(dQ)/(dT)`B. `dQxxdT`C. `sumQ.(1)/(dt)`D. none of these
Given that: `2C(s)+O_(2)(g)to2CO_(2)(g)" "(DeltaH=-787kJ)` . . . (i) `H_(2)(g)+1//2O_(2)(g)toH_(2)O(l)" "(DeltaH=-286kJ)` . . . (ii) `C_(2)H_(2)+2(1)/(2)O_(2)(g)to2CO_(2)(g)+H_(2)O(l)" "(DeltaH=-1310kJ)` . . .(iii) The heat of formation of acetylene is:A. `-1802kJ" " mol^(-1)`B. `+1802kJ" "mol^(-1)`C. `+237kJ" "mol^(-1)`D. `-800kJ" "mol^(-1)`
A gas can expand from `100 mL` to `250 mL` under a constant pressure of `2` atm. The work done by the gas isA. `30.38` jouleB. `25` jouleC. `5 k` jouleD. `16` joule
The free energy change for the following reactions are given below `C_(2)H_(2)(g)+(5)/(2)O_(2)(g)to2CO_(2)(g)+H_(2)O(l)`, `DeltaG^(@)=-1234 kJ` `C(s)+O_(2)(g)toCO_(2)(g)`, `DeltaG^(@)=-394 kJ` `H_(2)(g)+(1)/(2)O_(2)(g)toH_(2)O(l)`, `DeltaG^(@)=237 kJ` What is the standard free energy change for the reaction `H_(2)(g)+2C(s)toC_(2)H_(2)(g)` ?A. `209 kJ`B. `-2259 kJ`C. `+2259 kJ`D. `209 kJ`
The specific heat at constant volume for a gas is 0.075 cal/g and at constant pressure it is 0.125 cal/g. Calculate, (i) the molecular weight of gas, (ii). Atomicity of gas.
Assertion:Absolute values of intenal energy of substances cannot be determined. Reason:It is impossible to determine exact values of constituent energies of the substances.A. If both ther assertion and reason are true and the reason is the correct explanation of the assertion.B. If both the assertion and reason are true but reason is not the correct explantion of the assertion.C. If the assertion is true but reason is false.D. If assertion is false but reason is true.
`F_(2)C=CF-CF = CF_(2) rarr F_(2)underset(FC=)underset(|)(C)-underset(CF)underset(|)(CF_(2))` For this reaction (ring closure), `DeltaH =- 49 kJ mol^(-1), DeltaS =- 40.2 J K^(-1) mol^(-1).Up` to what temperature is the forward reaction spontaneous?A. `1492^(@)C`B. `1219^(@)C`C. `946^(@)C`D. `1080^(@)C`
For the reation `F_(2)(g)+2HCL(g)rarr2HF(g)+C1_(2)(g)` `DeltaH^(@)` at `298K` is `-84.4Lcal` , `DeltaH^(@)f(HF)=-64.2Kcal//mol` `DeltaH^(@)f` for the `HCL(g)` per gram isA. `-0.603Kcal`B. `-0603cal`C. `0.0603Kcal`D. `6.03Kcal`

Discussion

No Comment Found

Related InterviewSolutions

Reply to Comment