Question

Question #410dd

Answer 1

A) `2`

Explanation:

The van't Hoff factor, `i`, tells you the ratio that exists between the number of moles of solute dissolved in water and the number of moles of particles of solute produced in solution.

`i = "what you get in solution"/"what you dissolve to make the solution"`

Potassium hydroxide, `"KOH"`, is a soluble ionic compound, which means that it dissociates completely to form potassium cations and hydroxide anions

`"KOH"_ ((aq)) -> "K"_ ((aq))^(+) + "OH"_ ((aq))^(-)`

Notice that every `1` mole of potassium hydroxide that dissolves in solution produces

• one mole of potassium cations, `1 xx "K"^(+)`
• one mole of hydroxide anions, `1 xx "OH"^(-)`

This means that for every mole of potassium hydroxide you dissolve in solution, you get `2` moles of particles of solute.

Therefore, the van't Hoff factor will be equal to `2`

`i = (1 color(red)(cancel(color(black)("mole K"^(+)))) + 1 color(red)(cancel(color(black)("mole OH"^(-)))))/(1color(red)(cancel(color(black)("mole KOH")))) = 2`

You can thus say that

`color(darkgreen)(ul(color(black)(i = 2))) ->` you get twice as many moles of particles of solute in solution than the number of moles of solute you dissolved to make the solution