The problem of the conservation rate of chemical mass, the phenomenon of the law of conservation of

Start a, bc, 10g each of the three substances

A completely reacts A reacts 10 g

A + C = ==B (catalyst) ==D

10 x 16

Product D is 16g

Reactant C is kept according to chemical quality

Used 16-10 = 6g

c10-6=4g remaining

b is the same mass of the catalyst during the reaction!

The mass ratio of b to c is 10:4=5:2

According to the title, the chemical equation is like this:

ba + c = d

10g 16g

b is a catalyst, and the mass does not change before and after the reaction, so it is still 10 grams.

According to the conservation of mass, A reacts completely, indicating that A consumes 10 grams, but only 16 grams of substance D is generated, indicating that C has not finished the reaction and only consumes 16-10 = 6 grams (subtracting the mass of A participating in the reaction from the mass of D generated by the reaction is equal to the mass of C participating in the reaction), so the remaining mass of C is 10-6=4 grams.

Then the mass ratio of the mixture B to C after the reaction is 10:4=5:2

The reaction is a + c --d

The mass conservation rate shows that b = 10g (b is the catalyst mass unchanged) d = 16g Since a complete reaction, 10g before the reaction and 0 after the reaction. A to **?

Converted to d, but d is 16 g, how did the extra 6g come from, it is c conversion.

That is, C has converted 6g, and C has 4g left after the reaction.

The mass ratio of b to c is 10:4.

b: c= 5 : 2

Because B is a catalyst, the mass of B does not change before and after the reaction. So only the total mass of the three substances of ACD is conserved.

Before the reaction, A10 g, C10 g, D no, 0 g. Total mass = 10 + 10 = 20 grams.

After the reaction, the title says that A has a complete reaction, that is, A is gone, and D is 16 grams, indicating that C still has 20-16 = 4 grams, so the mass ratio of B to C in the reaction mixture is 10 : 4 = 5:2

a+c=20

A reacts all and generates d as 16 grams, then c is 20-16 = 4 grams.

Since the catalyst reaction is unchanged before and after, b is 10 grams.

Therefore, the mass ratio is: 10:4

b Because it is a catalyst, the mass before and after is unchanged to 10g; a complete reaction, so 0g remaining; D is generated by A and C, so the mass of D is the sum of A and C of the reaction, so C reacts D-A=16-10=6G, and the remaining C10-6=4G; Therefore, the mixture after the reaction b:c=10:4=5:2

Wrong. 1. All chemical reactions obey the law of conservation of mass.

2. The so-called non-conservation is actually not taking into account all matter. For example, magnesium belts and mountain exacerbation burn in oxygen to become magnesium oxide. According to the law of conservation of mass, the sum of the masses of magnesium bands and oxygen participating in the reaction = the only magnesium oxide that is produced after the reaction.

However, if only the amount of magnesium band and magnesium oxide is considered, it can be described as the mass gain of the magnesium band after combustion in oxygen.

3. The law of conservation of mass describes the conservation of mass, not of volume.

4. The law of conservation of mass is the total mass conservation of the chemical reaction itself, which has nothing to do with the outside world. Therefore, when verifying the law of conservation of mass experiment, a closed experimental setup should be used as much as possible to reduce interference.

1. The law of conservation of mass means that in a chemical reaction, the sum of the masses of the substances participating in the reaction is equal to the sum of the masses of the substances formed after the reaction. The root cause is explained from a microscopic perspective: before and after a chemical reaction, the type, number, and mass of atoms remain the same.

2. Understanding of the law of conservation of mass.

1) "Chemical reaction" is the premise. The scope of application of the law of conservation of mass is chemical change, not to physical change, and any chemical change follows the law of conservation of mass.

2) "Participation in the reaction" is the basis. The concept clearly states that it is the sum of the masses of the substances that "participate in the reaction", and the mass of substances that do not participate in the reaction cannot be counted.

3) "Sum of Quality" is the core. Whether it is the substance participating in the reaction or the substance formed after the reaction, neither item can be omitted in the calculation.

4) "Conservation of mass" is the goal. The fixed-wheel attitude law only applies to the conservation of "mass", excluding the conservation of volume and the conservation of the number of molecules.

Floor. Mass is not an approximation and is absolutely conserved.

In fact, how to put it, e=mc2 is not something that can be used casually, and it does not represent the whole amount of energy. For example, if you use e=mc2 when an object is at rest, what if it moves? Or e=mc2?

Obviously not, it still has kinetic energy. Generally speaking, this equation is only used in secondary school for nuclear calculations and nothing else. In the example you mentioned, it is not the mass that causes the change in energy, but the recombination and breakage of the bonds.

So, hehe, it can't be counted like that.

The change in the energy of a chemical reaction involves a change in the bond energy. For example, 2H2+O2=2H20 is seen as the H-H break and the O-O break absorb energy, and the H-O formation releases energy.

In this way, there is an energy difference.

When we say this, this substance does not only have mass, but also energy, and energy cannot be called. In this way, it can be seen that the energy that previously existed in the matter (not the mass becomes energy) is released (or absorbed and stored in the matter) through the reaction.

Another analogy:

With the same quality of water, one cup is 50 degrees Celsius or one cup is 10 degrees Celsius, which one has more energy? It is clear that the high temperature of the multi-point energy, but the mass does not increase. Because it's the energy that is added, not the mass.

Therefore, the conservation of mass is strictly observed before and after the reaction.

Again. e=mc²

Obviously, the question you asked was constructive. I have to admire your cleverness.