Question

В какой массе воды надо растворить 67,2 г хлороводорода, чтобы получить 9%-ый паствор хлороводородной кислоты.

Answer 1

В 100 граммах раствора должно содержаться 9 граммов хлороводорода. 67.2 граммов его должно содержаться в 67,2*100/9 = 746,7 граммах раствора. Следовательно, масса необходимой воды равна 746,7 - 67,2 = 679,5 грамма.

Answer 2

Calculating the Mass of Water Needed to Dissolve 67.2g of Hydrochloric Acid

To calculate the mass of water needed to dissolve 67.2g of hydrochloric acid and obtain a 9% solution of hydrochloric acid, we can use the formula for calculating the concentration of a solution:

Concentration = (Mass of solute / Mass of solution) × 100

In this case, the mass of the solute is 67.2g, and the concentration of the solution is 9%. We need to find the mass of the solution (water) required.

Calculation

Using the formula above, we can rearrange it to solve for the mass of the solution:

Mass of solution = (Mass of solute / Concentration) × 100

Plugging in the values: Mass of solution = (67.2g / 9%) × 100

Result

Calculating the mass of the solution gives us: Mass of solution = (67.2g / 0.09) = 746.67g

Therefore, to obtain a 9% solution of hydrochloric acid, 746.67g of water is needed to dissolve 67.2g of hydrochloric acid.