Tag: study of enthalpy

Questions Related to study of enthalpy

Multiple choice chemistry occurrence of carbon compounds in nature calorific value study of enthalpy chemical thermodynamics

Gross & net calorific value is the same for ___________.

  1. blast furnace gas

  2. coke oven gas

  3. L.D. converter gas

  4. none of these

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Gross & net calorific value is the same for L.D converter gas. Calorific value is the total quantity of heat liberated by the complete combustion of a unit mass of the fuel in air or oxygen. It is expressed in $kcal/m^3$ or British thermal unit (B.T.U) per cubic foot.

Multiple choice chemistry occurrence of carbon compounds in nature calorific value study of enthalpy chemical thermodynamics

Which among the following is the best fuel?

  1. Wood with calorific value 4000 Cal/g

  2. Coke with calorific value 8000 Cal/g

  3. Coal with calorific value 7000 Cal/g

  4. Kerosene with calorific value 11,200 Cal/g

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Higher the heating value or higher the calorific value better the fuel is, so kerosene has a higher heating value which is measured by bomb calorimeter.

Multiple choice chemistry occurrence of carbon compounds in nature calorific value study of enthalpy chemical thermodynamics

The heat produced by burning 1 g of fuel completely is known as _____________.

  1. heat capacity

  2. calorific value

  3. vapour density

  4. boiling point

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

 Calorific value is the quantity of heat produced by the complete combustion of a given mass of a fuel, usually expressed in joules per kilogram. It can be defined as the amount of heat energy produced on complete combustion of 1 Kg of fuel.


Hence, the correct option is $\text{B}$

Multiple choice chemistry occurrence of carbon compounds in nature calorific value study of enthalpy chemical thermodynamics

A family consumes 12 kg of LPG in 30 days. Calculate the average energy consumed per day if the calorific value of LPG is 50 kJ/kg.

  1. 10,000 J/day

  2. 15,000 J/day

  3. 20,000 J/day

  4. 25,000 J/day

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Energy released by 12 kg of LPG =  12 %$\times$ 50 kJ $= $ 600 kJ
$\therefore$ 
energy consumed per day
$\displaystyle \frac {600\,kJ}{30}\, =\, 20,000$ Joules/day.

Multiple choice chemistry occurrence of carbon compounds in nature calorific value study of enthalpy chemical thermodynamics

The calorific values of wood, bituminous coal, natural gas and charcoal vary in the order:

  1. wood > bituminous > natural gas > charcoal

  2. wood > bituminous coal > charcoal > natural gas

  3. natural gas > charcoal > bituminous coal > wood

  4. natural gas> bituminous coal> wood> charcoal

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Natural gas         $ = 43000 kJ/kg$

Charcoal             $ = 29600 kJ/kg$
Bituminous coal $ = 23250 kJ/kg$
Wood                   $  =  17400 kJ/kg$