Calculate the mass of KOH in a 35% solution that contains 58.5 g of water.

Approximately .

Explanation:

The mass of a solution can be divided into two parts:

In this particular solution in water,

The number here likely refers to the concentration of in this solution. That's ratio between the mass of the solute () and the mass of the whole solution (mass of solute plus mass of solvent.) That is:

.

Hence, .

However, since the solution contains only the solute and the solvent, .

For this solution in particular,

.

As a result,

.

Subtract from both sides of the equation:

.

.

Note, that for this calculation, there's nothing special about this solution of in water. In general,

.

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.

in the analysis of systems that involve fluid flow, we frequently encounter the combination of properties u and pv.