The fuel with highest calorific value in kJ /kg unit is-
Understanding Fuel Calorific Value and Energy Output
The calorific value of a fuel is the total energy released as heat when a unit amount (mass or volume) of the fuel is completely burned in oxygen. It's a measure of how much energy we can get from a specific amount of fuel. The unit for calorific value by mass is commonly expressed in kilojoules per kilogram ($\text{kJ/kg}$). Different fuels release different amounts of energy when burned.
Comparing the Calorific Value of Common Fuels
Let's look at the approximate calorific values of the fuels listed in the options (CNG, LPG, Petrol, and Hydrogen) to determine which one yields the most energy per unit mass. Note that these values can vary slightly based on the exact composition and source of the fuel, but the relative ranking is generally consistent.
| Fuel | Approximate Calorific Value ($\text{kJ/kg}$) |
|---|---|
| CNG (Compressed Natural Gas) | ~ 50,000 |
| LPG (Liquefied Petroleum Gas) | ~ 55,000 |
| Petrol (Gasoline) | ~ 45,000 |
| Hydrogen ($\text{H}_2$) | ~ 150,000 |
From the table, we can clearly see that Hydrogen has a significantly higher calorific value compared to CNG, LPG, and Petrol. Hydrogen's calorific value is roughly three times that of LPG, which is the next highest among the options provided. This means that burning one kilogram of Hydrogen releases about three times more energy than burning one kilogram of LPG.
Therefore, among the given options, Hydrogen is the fuel with the highest calorific value in $\text{kJ/kg}$ unit.
Important Questions from Thermodynamics
If the work done on the system or by the system· is zero, which one of the following statements for a gas kept at a certain volume is correct?
A system that does NOT allow exchange of heat with its surrounding is called
A system that does NOT allow exchange of heat with its surrounding is called
For a certain reaction, ΔG θ = -45 kJ/mol and ΔH θ = -90 kJ/mol at 0 °C. What is the minimum temperature at which the reaction will become spontaneous, assuming that ΔH θ and ΔS θ are independent of temperature?
- Which of the following statements correctly describes the thermodynamic classification of entropy?
