How to convert percentage concentration and mass volume concentration

If the percentage concentration is w and the mass and volume concentration is ρ, they are all SI units, the conversion relationship is as follows
w=ρ/d
Where D is the density of the solution in kg / L

How to convert mass concentration to volume concentration?

In the case of gas, there is the following relationship between mass concentration cm (mg / m3) and volume concentration CV (in ml / m3) under standard conditions:
cv=22.4Xcm/M
M is the molecular weight of a gaseous substance

How to convert the mass percentage concentration and the mass concentration of the substance,

The weight of the solution is first converted to the volume of the solution, and the solute remains unchanged
The density of the solution needs to be involved
Solution weight / solution density = solution volume
Solute weight = mass percentage concentration * solution weight
Solute weight (g) / solute molar mass / solution volume (L) = solution concentration (mol / L)

There are two boxes of apples in the fruit shop with the same quantity. The first box sold 5 / 3, and the second box sold 30%. Then take six apples out of the second box and put them into the first box. At this time, the ratio of the first box to the second box is 5:6?

It should be sold for 3 / 5. Suppose there are x in a box. Wait until the formula (0.4x + 6) / (0.7x-6) = 5 / 6
We can get 2.4x + 36 = 3.5x-30. We can get x = 60, so there are 120

1. It is known that x + 2Y = 5, when x = - 1, y = (); when y = - 4, x = () 2. It is known that a and B satisfy 3a-2b = 10, and the formula of B expressed by a is (); B is expressed by A
The formula of is ()
3. Given that x = - 2, y = 1 satisfies the equation kx-3y = 6, then k = ()

1. When x = - 1, y = 3; when y = - 4, x = 13;
2.b=(3a-10)/2
a=(10+2b)/3
3.-9/2

The store brought in some apples, pears and peaches. Among them, apples are 300kg and pears are 500kg. The weight of apples and pears accounts for 80% of the total weight of these fruits. How many kg of apples, pears and peaches do the stores bring in? What percentage of apples, pears and peaches account for the total weight of these fruits?

300 + 500 = 800, 800 / 80% = 1000, peach: 1000-800 = 200kg,
Apple; 300 / 1000 = 30%
Pear; 500 / 1000 = 50%
Peach; 200 / 1000 = 20%
A: Apple 300 kg, accounting for 30%
Pear 500 kg, accounting for 50%
Peach 200kg, accounting for 20%

How many faces does a geometry have if it has 8 edges and 5 vertices?
If it was in the book, would I need to ask such a lot of questions?

5ge mian

Calculus topic, on the polar coordinates of double integral, as shown in the figure

The original formula = ∫ (- π / 2, π / 2) d θ∫ (0,2cos θ) f (PCOS θ, PSIN θ) pdpd θ

The father gazed at his son who was half a head taller than himself, and he couldn't shut his mouth happily

Gaze is to look without blinking an eye; to look with concentration; to look without turning one's eyes; to look with concentration
The father looked at his son who was half a head taller than himself, and he couldn't shut his mouth happily

Sum Sn = 1 / A + 1 / A & # 178; +. + A ^ n
Do you use the multiplication and common ratio dislocation subtraction method? What formula can it turn into?

It is to multiply by the common ratio and subtract by dislocation. Finally, it turns into Sn = (1-1 / (a ^ n)) * 1 / (A-1). I've calculated it seriously, and I hope the landlord can adopt it

How to convert percentage concentration and mass volume concentration