The calorific value is a kind of fuel , which is related to , not and .

Caloric value. It is a (characteristic) of the fuel, regardless of the (mass) and (combustion condition) of the fuel.

Calorific value, also known as calorie value or calorific value.

In fuel chemistry, it is an important indicator of fuel quality. The amount of heat emitted per unit mass (or volume) of fuel when it is completely combusted. It is usually determined with a calorimeter (calorimeter) or calculated from the results of a fuel analysis. There are high and low calorific values.

Both. The former is the heat of combustion of the fuel.

and the total amount of heat of condensation of water vapor, i.e. the total amount of heat emitted when the fuel is completely combusted. The latter is simply the heat of combustion of the fuel, i.e. the difference between the total heat minus the heat of condensation. Commonly used units of calorific value, J kg (solid and liquid fuels), or J m 3 (gaseous fuels).

The heat emitted by the complete combustion of 1 kilogram of a certain solid (gaseous) fuel is called the calorific value of the fuel, which belongs to the properties of the substance, the symbol is q, and the unit is joules.

For each kilogram, the symbol is j kg. The calorific value reflects the combustion characteristics of the fuel, i.e., the chemical energy of different fuels during combustion.

The size of the ability to convert into internal energy.

Extended information: Formula for calculating the heat released by the complete combustion of solid or liquid fuels: q amplification = mq Formula for calculating the heat released from the complete combustion of gaseous fuels: q=vq q q is the heat (j) and q is the calorific value (

j kg, m is the mass of solid fuel (kg), v is the volume of gaseous fuel (m3).

q=qput m(solid); q=q discharge v (gas).

w=qm=qm=qm

w=qv=qv

W: total work) calorific value is related to pressure, SI SI unit.

Q——— the amount of heat emitted after the complete combustion of a certain fuel ——— joules j

m——— indicates the mass of a certain fuel ——— kilograms

Q——— indicates the calorific value of a certain fuel ——— joules per kilogram.

To understand this question, we must first understand the definition of calorific value:

The heat emitted by the complete combustion of 1 kilogram (per cubic meter) of a certain solid (gaseous) fuel is called the calorific value of the fuel, which belongs to the characteristics of the substance, the symbol is q, the unit is joules per kilogram, and the symbol is j kg (j m 3). The calorific value reflects the combustion characteristics of fuels, that is, the ability of different fuels to convert chemical energy into internal energy during combustion.

From the definition, it can be seen that calorific value is a property of a substance, independent of the mass of the substance itself.

I think maybe the teacher was talking about calories!

Give yourself the best answer, and if there is a mistake you want to point out,!

Calorific value is a property of a fuel, which is only related to the type of fuel, not the quality of the fuel.

Calorific value is a characteristic of a fuel and is independent of its mass and combustion status.

In fuel chemistry, calorific value is an important indicator of fuel quality. The amount of heat emitted per unit mass (or volume) of fuel when it is completely combusted.

It is usually determined with a calorimeter (calorimeter) or calculated from the results of a fuel analysis. There are two types: higher calorific value and lower calorific value. The former is the total amount of the heat of combustion of the fuel and the heat of condensation of the water vapor, that is, the total amount of heat emitted when the fuel is completely combusted.

The latter is simply the heat of combustion of the fuel, i.e. the difference between the total heat minus the heat of condensation.

Commonly used units of calorific value, J kg (solid and liquid fuels), or J m 3 (gaseous fuels). The correct use of microcomputer calorimeter and lifting microcomputer automatic calorimeter can test the calorific value of coal. In food chemistry, an indicator that represents the energy of food.

Refers to the amount of heat emitted by 1g of food when it oxidizes in the body.

Characteristics Temperature Mass Volume Thank you Adopted.

a. The calorific value of the fuel is related to the type of fuel, and has nothing to do with the quality and combustion status of the fuel, which is in line with the meaning of the topic b. The heat released by burning 1 kilogram of a certain type of fuel is called the calorific value of the fuel, which must be the heat released by complete combustion, which is the calorific value of the fuel, which does not meet the theme

c. When the fuel is burned, the greater the mass, the greater the calorific value: the calorific value has nothing to do with the mass, only with the type of fuel, which does not conform to the topic

d. The calorific value of the fuel when it is not completely burned is smaller than the calorific value when it is completely combusted, and the heat released when the fuel is not completely burned can not be called the calorific value, which does not meet the meaning of the topic, so choose A

a. The calorific value is fuel.

A characteristic, which is only related to the type of fuel, and has nothing to do with the quality of the fuel, the degree of combustion, etc.

Capacitance B, calorific value has nothing to do with whether the fuel is easy to burn, so B is wrong;

c. The amount of heat released by fuel combustion is not only related to the calorific value of the fuel, but also related to the quality of the fuel and the degree of combustion, so C is wrong;

d. The calorific value of coal is greater than that of dry wood, because the heat released is related to the quality of the fuel and the degree of combustion, so the heat released by burning coal is not necessarily more than the heat released by burning dry wood, so D is wrong;

So choose A

Answer AA, the calorific value of the fuel is related to the type of fuel, and has nothing to do with the quality and combustion status of the fuel, which is in line with the topic

b. The heat released by burning 1 kg of a certain fuel is called the calorific value of this fuel, and it must be the heat released by complete combustion to be the calorific value of the fuel, which does not conform to the topic

c. When the fuel is burned, the greater the mass, the greater the calorific value: the calorific value has nothing to do with the mass, only with the type of fuel, which does not conform to the topic

d. The calorific value of the fuel when it is not completely burned is smaller than the calorific value when it is completely combusted, and the heat released when the fuel is not completely burned can not be called the calorific value, which does not meet the meaning of the topic, so choose A

I don't think there is a correct answer here, a, there is a lot of chemical energy, but it may not be combustible, such as polymer high-temperature resistant organic matter. b。Easy to burn means that its ignition point is low, and the ignition point is not necessarily related to the calorific value.

d can be considered to be correct in junior and senior high school, but the essence of calorific value is the breakable chemical energy, and the chemical energy here includes the unbreakable chemical energy under combustion conditions. I recommend that if you encounter it in the exam, I recommend choosing D

The calorific value of the option d reflects an ideal result and refers to the heat emitted by the complete combustion of 1 kg of fuel.

Item A is correct, the calorific value of the fuel has nothing to do with the combustion, the calorific value is the physical property of the fuel itself, and the error is that the calorific value of the fuel that is easy to burn is not necessarily large, for example, the flammable calorific value of alcohol is much lower than that of non-flammable standard coal.

The error of item C is that the calorific value of coal is high and low, and the calorific value of coal with low calorific value is not necessarily higher than that of firewood, and the error of item D lies in the need for boiler efficiency to reduce various energy losses and strengthen operation adjustment, and the boiler can not burn coal with too high calorific value, especially for modern high-temperature and high-pressure boilers in power stations, and low calorific value of lean coal or lignite should be used for coal burning.

a. The calorific value of the fuel has nothing to do with the combustion of the fuel, it is only related to the type of fuel, so A is in line with the topic

b. The calorific value has nothing to do with whether the fuel is easy to burn, it is only related to the type of fuel, so B does not meet the topic

c. The amount of heat emitted by fuel combustion is not only related to the calorific value of the fuel, but also related to the quality of the fuel and the degree of combustion, so C does not meet the topic

d. The efficiency of the boiler has no relationship with the high calorific value of the fuel, so D does not meet the topic, so choose A

Answer: D1kg The energy released by the complete combustion of a certain burning letter is called the calorific value of this fuel The calorific value is a characteristic of the fuel, which is only related to the type of fuel, and the quality of the fuel, the degree of combustion, etc., so ABC is wrong, D is correct"

Answer B analysis: The calorific value of fuel is the heat released by the complete combustion of 1kg of a certain fuel, which is only related to the type of fuel, and the quality of the fuel, whether the fuel is burned, whether the fuel is completely burned and other factors have nothing to do with the quality of the fuel in A, the easy combustion in C does not represent the calorific value, and the improvement of the utilization rate of fuel in D lies in the utilization of the energy released by a certain auspicious grinding fuel has nothing to do with the calorific value