Does the total molar mass of a substance change before and after a chemical change??????????????????

According to the chemical formula, the total molar mass of a substance before and after the chemical change is constant. It can also be said to conform to the law of conservation of mass. However, in actual experiments, we know that many of the products are gaseous and will disappear when dispersed in the air, and if the mass of the products is compared with the reactants by weighing the mass of the products, it is obvious that the mass of the products will be less than the mass of the reactants.

For example, CaCO3+2HCl===CaCl2+H2O+CO2 (arrow pointing up).

Molar mass (g mol) 100 2* 111 18 44 Total molar mass (173) 173).

In summary, the total molar mass of the species before and after the reaction is equal.

If you're not equal, it's likely that you haven't balanced yet.

Actually, ......LZ's question is a bit of a problem......

The total mass before and after the chemical reaction is a constant .........

Molar mass is a ...... unique to each substanceIt should be said that it is a property......For example, ......The molar mass of O2 is 32g mol and H2O is 18g mol......Regardless of the chemical reaction, their molar mass is ...... that never changesNot to mention the "total molar mass" .........

To say the total mole count ......is a ...... that can change

For example, H2 + Cl2 = (ignition) = 2HCl is a substance of two moles before the reaction and two moles of a substance after the reaction......It's an immutable ......However, N2 + 3H2 = (high temperature and high pressure) = 2NH3 is a substance of 4 moles before the reaction and 2 moles of the substance after the reaction ......So the ......... changed

This, really unchanging, must know that matter is conserved.

Unchanging. Just like that, do you still want positive and negative particles to be annihilated......Well, too much.

Summary. Dear dear, it's a pleasure to answer your <>

The total number of moles of substances before the chemical reaction is not necessarily the same as the total number of moles of substances after the reaction. <>

The mass of the substance before and after the reaction is equal, but the molar mass of the substance before and after the reaction is not equal, so the amount of the substance before and after is not necessarily equal. <>

Is the total number of moles of a substance before a chemical reaction equal to the total number of moles of a substance after a reaction?

Dear dear, it's a pleasure to answer your <>

The total number of moles of substances before the chemical reaction is not necessarily the same as the total number of moles of substances after the reaction. <>

The mass of the substance before and after the reaction is equal, but the molar mass of the substance before and after the reaction is not equal, so the amount of the substance before and after is not necessarily equal. <>

Mole is a unit of quantity of matter, and each mole contains particles of Avogadro's constant. Moore, abbreviated as mole, is a unit of quantity of matter and is one of the seven basic units of the International System of Units. Molar Mass Concept:

Any particle or substance of 1mol, when its mass is measured in grams, is numerically equal to the relative atomic mass or relative molecular mass of that particle. The mass possessed by a substance as a unit of quantity is called molar mass. <>

Summary. No, molar mass in physics refers to the mass of 1 mol of matter, while molar mass in chemistry refers to the mass of 1 mol of matter. Thus, molar mass in physics and molar mass in chemistry are different concepts.

Molar mass in physics refers to the mass of 1 mol of a substance, while molar mass sensitive band in chemistry refers to the mass of a 1 mol substance. Therefore, the quality of Moore in physics and the molar mass in chemistry are different concepts.

I'm sorry I don't understand, but can you elaborate on that?

Molar mass in physics refers to the mass of 1 mol of a substance, while molar mass sensitive band in chemistry refers to the mass of a 1 mol substance. Therefore, the quality of Moore in physics and the molar mass in chemistry are different concepts.

Summary. Hello, this question for you must be wrong, because the units are not the same.

However, it can be understood in this literal sense: the molar mass of a substance is the mass per mol of matter. The mass per mole of matter, or the mass per mol of matter.

Molar mass is the mass of 1mol of substance, how to change if wrong.

You are cautious, you must be wrong in this matching, because the units are not the same, but it can be understood literally like this: the molar mass of a substance is the mass per mol of substance. The mass per mole of a substance, or the mass unit per mol of a substance, is g mol (grams per burn sold to the mole), and I hope it can help you.

Is the mass of a substance numerically equal to its molar mass" is true?

Hello, this sentence is also wrong, this sentence does not say what kind of substance cannot be replaced by a substance.

The molar mass of HCl is equal to the mass of 1mol HCl molecule, right, reason? ☺

Hello, no, the shell is a gas, to use the molar volume, the standard condition of the molar mass is limited to the solid, the amount of silver substance that the content of the piece is for the solid, gas, liquid separately.

What are you talking about? What is called only for solids,.

The reason is wrong. Hello, what's wrong? You haven't made it clear on your side, you have to make it clear, what is the state of your side? You have to make it clear.

No matter what the state, the amount of its substance is 1mol, does it have anything to do with the state?

The unit of molar mass: g mol. Unit of mass: g. The units are different and cannot be compared.

The amount of matter – n

The mass of the substance – m

Molar mass – m

Number of particles – n

Avogadro's constant – Na

Relative atomic Mass – Ar

Relative molecular weight – mr

Mass Score – W

The molar volume of the gas - vm - l mol - in standard conditions, i.e. at 0 degrees Celsius 101 kPa).

The amount and concentration of the substance - CB (B in the lower right corner of C) - the amount of mol l substance (mol) = the mass of the substance (g) The molar mass of the substance (g mol) is expressed as the physical quantity of the solution composition by the amount of solute B (B represents various solutes) contained in the unit volume of the solution, which is called the amount concentration of the substance of solute B.

Common unit: mol l or mol m3

The volume of the gas v = the amount of matter (mol) x the molar volume of the gas (vm) six. The relationship between the mass fraction of solute, the amount and concentration of the substance, and the density of the solution w=(c*1l*m) (1000ml*density)*100 Expand:

c = (1000·a%·density) m

Molar mass. Refers to:

The weight of one mole of matter. Numerically equivalent to the relative atom (molecule.

particulate on the line) quality.

It's like water. （h2o）

Its molar mass is 18g mol

The amount of matter. It refers to a bridge that connects the weight of macroscopic matter with the quantity of microscopic substance. Usually.

It is also calculated in conjunction with the Avogadro constant (naa should be subscripted. The negative of the 23rd power mol is squared.

Sorry, it's a bit messy. Can't hit the upper and lower subscripts.

Like. 1molh2o

It has 1 na water molecules and weighs 18 g

n (number of particles) = n (amount of matter) * na (Avogadro's constant).

The quantity of matter is a collective concept that cannot be used separately where there are particles (molecules) that have the same as atoms. Atom. Ion. Let's say that the amount of the substance is 1mol

Molar mass: The mass possessed by a substance in the amount of a unit of substance. For example, the mass of any atom in 1 mol is numerically equal to its relative atomic mass and is measured in grams, i.e., the molar mass of a hydrogen atom is 1g mol....For example, the mass of any molecule in 1 mol is numerically equal to its relative molecular mass and is measured in grams, i.e., the molar mass of a hydrogen molecule is 2g mol....For example, the mass of 1 mol of any ion is numerically equal to its formula and is measured in grams, i.e., the molar mass of a hydrogen ion is 1g mol....The mass of matter, which is the amount of matter contained in an object, is an intrinsic property of matter.

Relative atomic mass: The ratio of the mass of the atom to the mass of the c-12 atomic mass of 1 12, which is a measure of the size of the atomic mass; The relative molecular mass is similar to the former;