A chemistry question about a solution, ask a chemistry question about a solution

98%m1=600g*20%

m1=v=m/p=

80%*5g 50g*x y z

100/71=4g/50gx

x = The result after the reaction is a calcium chloride solution, and the mass of the solute calcium chloride can be obtained from the chemical equation.

y = mass of the solution equal to the mass of limestone (excluding impurities) plus the mass of the hydrochloric acid solution minus the mass of the gas carbon dioxide generated.

z = solution mass = 80% * 5g+

The solute mass fraction in the solution obtained after the reaction =

The numbers don't look too neat, and the method should be fine.

Sodium chloride: 100g* water.

1. The actual solute mass fraction of the sodium chloride solution he prepared is (

2. Weigh 1g of sodium chloride and add it to the sodium chloride solution prepared by him.

1. It depends on how you understand this.

If you say that you want to dissolve a substance, and it turns out that the substance can react with water, and the result is not formulated, it is one.

A typical example is the preparation of a CaO solution, which results in a Ca(OH)2 precipitate.

Let's say you want to make a solution by reaction, and the result is that the product can react with water.

A typical example of this environment is the double hydrolysis reaction.

If Na2S and Al(NO3)3 are put together to prepare a mixed solution of Na3 and Al2S3, Al2S3 will be double hydrolyzed and precipitated.

If you want to discuss, the solute of a solution reacts with water to produce precipitation and does not count as a solution of this solute, then it does not count, it counts as a solution of substances formed after the reaction, because everything has solubility, you can go back to the example of CaO, and you get a calcium hydroxide solution instead of Cao, because there must be an excess of water.

2. Relevant. In general, there is the following formula.

c=1000*p*a%/m

Where: c denotes the amount of substance (mol).

p denotes the density of the solution (g ml).

a% indicates the quality score.

m denotes the molar mass (g mol) of the solute

3. Make it smaller. Without concentrated sulfuric acid water absorption, the solution mix always becomes smaller because there are gaps between molecules.

After mixing two kinds of stones, one large and one small, (it may be easier to understand as stones and sand), the total volume is less than the sum of volumes, and the same is true.

A typical example of this problem is when water and alcohol are mixed, and the result becomes smaller.

To prepare the solution, of course, you can't use a solvent that can react with the solute, the solution is the solute dissolved in the solvent, which is a physical reaction. If the solute is allowed to react chemically with the solution, it cannot be called a solution.

Not necessarily, for example, ammonia, the higher the concentration, the smaller the density.

Because the average gap between the molecules after mixing becomes smaller than the average gap before mixing.

It cannot be reacted, and it cannot be precipitated.

OK; Molecules have voids.