At a certain temperature, the density of the saturated solution of a substance with molar mass m is ρ, and the mass concentration of the substance is C? At a certain temperature, the density of the saturated solution of a material with a molar mass of M is ρ, and the mass concentration of the material is C. what is the mass fraction of solute in the solution? The answer of the exercise is (cm / 10 ρ)%, which is cm of 10 ρ, followed by a%,

At a certain temperature, the density of the saturated solution of a substance with molar mass m is ρ, and the mass concentration of the substance is C? At a certain temperature, the density of the saturated solution of a material with a molar mass of M is ρ, and the mass concentration of the material is C. what is the mass fraction of solute in the solution? The answer of the exercise is (cm / 10 ρ)%, which is cm of 10 ρ, followed by a%,

Let the volume of the solution be 1000 ml and the mass be 1000 ρ G
Amount of solute: C mol
Mass of solute: CMG
Mass fraction of solute: (CM) / (1000 ρ) = cm / (1000 ρ) = cm / (1000 ρ) * 100%
= cM/(10ρ) %

If the molar mass of a diatomic gas is mg / mol, the mass of the gas is m g and the Avogadro constant is Na, then
(1) What is the mass of the gas
(2) What is the volume of the gas under standard conditions
(3) What is the density of the gas under standard conditions, g / L
(4) What is the total number of atoms in the gas
(5) What is the mass of a molecule of the gas (expressed as Na)

(1) The mass of the gas is m / M mol (2). The volume of the gas in the standard state is m / m × 22.4 L (3). The density of the gas in the standard state is m / 22.4 g / L (4). The number of atoms in the gas is m / m × 2Na (5). The mass of a molecule of the gas is m / Na

If the Avogadro constant is expressed by Na, then: m g / mol
If the Avogadro constant is expressed by Na, then: m g / mol
(1) The amount of substance in the gas is_____ mol.
(2) The total number of atoms in the gas is_______ One
(3) The volume of the gas under standard conditions is__________ L.
(4) The gas is dissolved in 1 L water (regardless of reaction), and the mass fraction of solute in the solution is__ .
(5) The gas dissolves in water to form a V L solution, and the mass concentration of the solution is____ mol/L.
Small (4) need process, other as long as the answer is OK

(1) The amount of substance in the gas is_____ Divide the mass by the molar mass, i.e. M / m
(2) The total number of atoms in the gas is_______ Multiply the above result by Avogadro constant, i.e. MNA / m
(3) The volume of the gas under standard conditions is__________ 50. Multiply the result of the first question by 22.4, that is 22.4m/m
(4) The gas is dissolved in 1 L water (regardless of reaction), and the mass fraction of solute in the solution is__ Divide the mass of solute by the mass of solution, i.e. M / M + 1000g and multiply by 100%
(5) The gas dissolves in water to form a V L solution, and the mass concentration of the solution is____ Mol / L. divide the result of the first question by the volume of solution. M / MV
Small (4) need process, other as long as the answer is OK

It is known that the density of copper is 8.9 * 10 ^ 3kg / m ^ 3, and the molar mass of copper is 63.5 * 10 ^ (- 3) kg / mol
How many copper atoms are contained in the 4.5cm ^ 3 copper block? And what is the diameter of copper atoms?

The density of copper is 8.9g/cm ^ 3, the molar mass of copper is 63.5g/mol, and the volume of copper block is 4.5cm ^ 3, so the mass of copper block is 40.05g,
The amount of substance = mass / molar mass, so the amount of substance of copper block is 40.05g/63.5g/mol ≈ 0.631mol
Because the fractional number of 1 mol of any substance is 6.02 × 10 ^ 23
So the copper block contains 0.631 × 6.02 × 10 ^ 23 copper atoms
Because the volume of copper block is 4.5cm ^ 3, the volume of each copper atom is 4.5 ^ (0.631 × 6.02 × 10 ^ 23) cm ^ 3
According to the volume formula v = 4 / 3 π R ^ 3 (where V is the volume and π = 3.1415926. R is the radius of the copper atom), the diameter of the copper atom can be calculated