# Put 8 g of sodium hydroxide solid into 100 g of dilute hydrochloric acid and the reaction is just complete. Calculate the solute mass fraction of dilute hydrochloric acid

## Put 8 g of sodium hydroxide solid into 100 g of dilute hydrochloric acid and the reaction is just complete. Calculate the solute mass fraction of dilute hydrochloric acid

NaOH+HCl=NaCl+H2O
40 36.5
8g x
40/8g=36.5/x
x=7.3g
7.3g/100g*100%=7.3%

### What is the mass fraction of 100 grams of dilute hydrochloric acid that completely reacts with 80 grams of 10% sodium hydroxide

Set the mass of hydrochloric acid as X
HCl + NaOH = NaCl + H2OH
36.5 40
x 80*10%
36.5/x = 40/80*10%
x=7.3g 7.3/100 × 100%=7.3%
The mass fraction of dilute hydrochloric acid is 7.3%

### A sodium hydroxide solution with a mass fraction of 40% of 50 grams of solute was mixed with a sodium hydroxide solution with a mass fraction of 20% of 100 grams of solute, and the mass fraction of solute in the resulting solution was

The mass of solute in solution 1 is 50 * 40% = 20g. The mass of solute in solution 2 is 100 * 20% = 20g
Then the total mass of solute is 20 + 20 = 40g
The total mass of the solution is 100 + 50 = 150g
The mass fraction of the obtained solution is 40 / 150 = 26.67%

### 200g dilute hydrochloric acid is added into a beaker containing 50g calcium carbonate, and the reaction is just finished. Try to calculate the mass fraction of solute in the solution obtained after the reaction

Let the mass of CaCl2 generated by the reaction be x and the mass of CO2 generated be y. CaCO3 + 2HCl = CaCl2 + H2O + CO2 ↑ 100 111 4450g x y 100 / 50 = 111 / x = 44 / YX = 55.5g y = 22G. The mass of the solution after the reaction is 200g + 50g-22g = 228g

### Calcium carbonate reacts with dilute hydrochloric acid to form calcium chloride. Is the carbon dioxide generated in the equation of water and carbon dioxide precipitation? Excuse me, I want to ask, can the generated carbon dioxide be counted as a solution? For example, when doing a calculation problem, is it OK to calculate the mass of the solution?

It's not precipitation! Carbon dioxide is a gas! Calcium carbonate is precipitation, but it can't be written in the following chemical equation
CaCO3 + 2hci = = = = CaCI2 + H2O + CO2 ↑ (gas)

### Why does calcium carbonate react with dilute hydrochloric acid to produce carbon dioxide, water and calcium chloride instead of carbonate and calcium chloride?

Carbonic acid is unstable and easy to decompose into carbon dioxide and water