Question

If 17.8 grams of KOH dissolve in enough water to make a 198-gram solution, what is the concentration in percent by mass?. . A. 8.25% KOH. . B. 8.99% KOH. . C. 10.9% KOH. . D. 11.1% KOH

Answer 1

The correct answer is option B.

Step-by-step explanation:

Mass of potassium hydroxide =17.8 g

Mass of the solution = 198 g

Concentration in percent by mass:

`\frac{\text{Mass of solute}}{\text{Mass of the solution}}* 100`

So, the concentration in percent by mass of KOH will be:

`(17.8 g)/(198 g)* 100=8.98\%`

The closest answer to our answer is option B. Hence, the correct answer is option B.

Answer 2

Percent by mass or Mass percentage is one way of expressing concentration of a substance in a solution. It is the amount in units of mass of the substance divided by the total amount in units of mass of the solution multiplied by 100 percent. We calculate the above problem as follows:

(17.8 / 198 ) x 100% = 8.99% ----> OPTION B