All physical quantities in high school, and quantities of chemical substances in high school

High school chemical substance quantity related concepts:

1.The amount of matter.

1) Concept: A physical quantity that indicates the number of particles contained in a substance.

2) Symbol: n

3) Unit: mol

2.Moles. (1) Concept: Mole is a unit of quantity of matter, and every 1 mol of substance contains Avogadro's constant structural particles.

2) Symbol: mol

3) Description: When describing the amount of a substance (using moles), the name of the substance particle must be indicated, not the macroscopic substance name.

Common microscopic particles are: molecules, atoms, ions, electrons, protons, neutrons, or a specific combination of them.

When there is only one microscopic particle of some substances, its name can be omitted.

3.Avogadro's constant.

1) Meaning: Experimentally determine the number of carbon atoms in 12G12C.

2) Symbol: na

3) Unit: mol

4) Note: The benchmark for NA is the number of atoms in 12g of carbon-12.

12c is not only the reference object of moles, but also the reference object of relative atomic mass Na is an experimental value, which is often used as a calculation at this stage.

Pay attention to the difference between na and na.

4.Molar mass.

1) Concept: The quantity of a substance per unit of substance, the mass of a substance.

2) Symbol: M

3) Unit: g·mol-1

4) Description: Scope of use: aAny kind of microscopic particle bPure or notRegardless of the state of matter.

Comparison with formulas.

Comparison with the mass of 1mol of substance.

5.Molar volume of gas.

1) Concept: The volume of a gas per unit of substance.

2) Symbol: VM

3) Unit: l·mol-1

4) The molar volume of the gas under standard conditions.

Standard condition ATM i.e.

Ideal gas: aNot about the size, but about the quality.

b.Molecular interactions are not counted.

Molar volume of gas under standard conditions: approx.

5) Factors influencing the volume size of a substance:

The size of the particles that make up the substance (the nature of the substance).

The magnitude of the distance between structural particles (temperature and pressure are determined together).

The number of structural particles (the size of the amount of matter).

6.The amount of concentration of the substance.

1) Concept: The concentration of a solution is expressed by the amount of substances dissolved in a unit volume of solution.

2) Symbol: c

3) Unit: mol·l-1

4) Description: The quantity concentration of a substance is the volume concentration of the solution.

A solute in solution can be either a pure substance or a mixture, or it can refer to an ion or molecule.

The quantity of matter: is a fundamental physical quantity, which represents a collection containing a certain number of particles, with the symbol n. The unit is mole, referred to as mole, and the symbol is that the number of particles contained in the particle collective is the same as the number of carbon atoms contained in it, which is about.

1. Avogadro's constant: It is a physical quantity that can be defined as the number of particles contained in a substance per unit of matter. The symbol is na, and the unit is mol 1, which can be expressed as na= mol 1.

It is the ratio coefficient between the molar mass of the particle (i.e., the mass at one mole) and its mass.

2. Molar mass: The mass possessed by a substance as a unit of substance is called molar mass. The symbol is m, and the commonly used unit is g mol.

When the molar mass is measured in g·mol 1, it is numerically equal to the relative molecular mass or relative atomic mass of the substance. For a pure substance, its molar mass is fixed and constant, whereas the mass of a substance varies with the amount of matter of the substance.

3. Quantity and concentration of substance: The amount of solute B contained in the solution per unit volume represents the physical quantity of the solution and the concentration of the substance called solute B. The symbol is c (b), and the unit is mol l (or mol·l 1), etc.

The volume of the solution cannot be equated to the volume of the solvent, but should be the actual volume of the solute after it is dissolved in the solvent. Soluts can be substances or molecules or ions.

4. Gas molar volume: The volume occupied by the gas per unit of substance is called the gas molar volume, the symbol is vm, and the commonly used units are l mol or (l·mol 1) and m3 mol (or m3·mol 1). The molar volume of the gas varies at different temperatures and pressures.

In standard condition kpa), the molar volume of gas vm=.

5. Avogadro's law: At the same temperature and pressure, any gas of the same volume contains the same number of molecules. This law is called Avogadro's law.

Avogadro's law applies only to gases, not to solid and liquid substances. Only gases with the same temperature, pressure, and volume have the same number of molecules. VM is the embodiment of Avogadro's law.

The number of molecules is equivalent to the ratio of the number of molecules, and the ratio of the number of molecules is equal to the ratio of the amount of matter.

Specifically, analyze this question: a), mg

The quantity of a substance n(a) = the formula of m a m(a),n

The quantity of the substance of gb n(b) = the formula m (b), according to the title, n(a) = n (b), then: m travel trace m(a) = n m (b), that is: m (a) m (b) = m n.

b) The ratio of the number of molecules is equal to the ratio of the quantity of the substance. The mass of n(a)=a m(a), the mass of n(b)=b m(b), when the masses are equal to the front: n(a) n(b)=m(b) m(a), which is equivalent to n m.

c) According to the gas formula: pv=nrt, when p and t are the same, the ratio of the quantity of the substance = the ratio of volume, and the quantity of the substance = the mass of the formula, the density = the mass of the volume, it can be derived: the ratio of density = the ratio of the quantity of the formula.

That is: d(a) d(b) = m(a) m(b), which is equivalent to m n

d) According to the gas formula: pv=nrt, when p, v, t are the same, the quantity of the substance is the same, and the quantity of the substance = the mass of the quantity, therefore, when p, v, t are the same, the ratio of the mass = the ratio of the formula is equivalent to m n.

It can be seen that the statement (c) of this question is incorrect.

This is not memorized by people, and generally specific data will be given to the question, or to other people who ask you for these.

A basic quantity is:

1 Length (l) 2 Mass (m) 3 Time (t) 4 Current (i) 5 Thermodynamic temperature.

t)6 The amount of the substance.

n)7 Luminous intensity (i).

Note: The fundamental quantities to be distinguished from are that only the length, mass, and time within the mechanical range of physics are three SI units.

Fundamentals such as velocity, acceleration.

None of them.

The two units are:

5 Thermodynamic temperature: k open (Erwen) 6 Amount of matter: mol (mol) 7 luminous intensity: cd Kan (Dela).

Note: The units to be distinguished are: for example, the basic unit of SI units of length is only the meter, which cannot be said to be centimeters, nor can it be said to be yards.

Seven fundamental physical quantities: length m, time s, mass kg, thermodynamic temperature (Kelvin temperature) k, current unit a, light intensity unit cad (candela), quantity of matter mol

Categories: 1Mechanics Length (m) Mass (kg) Time (s) 2Electrical current (amps) 3Thermodynamics Temperature (Kelvin) Amount of matter (mol) 4Optical luminous intensity (candela).

Upstairs is. More generally, momentum p, energy e

Vectors: velocity, acceleration, displacement, force, acceleration, linear velocity, centripetal acceleration, electric field strength, magnetic induction intensity.

Scalar: mass, volume, density, length, time, rate, distance, frequency, period, work, power, energy, current, voltage, resistance, capacitance, magnetic flux, etc.

Time, distance, energy, electric potential,