A stock solution of calcium sulfate, CaSO4 has a concentration of 3.00 M. The volume of this solution is 150 mL. What volume of a 1.25 M solution could be made from the stock solution?

The volume of stock solution needed is 62.5 mL

Explanation:

A solution consists of solute and solvent. A solute is defined as the component that is present in a smaller proportion while the solvent is defined as the component that is present in a larger proportion.

To calculate the volume of stock solution needed, the formula used is:

            ....(1)

where,

are the concentration and volume of stock solution.

are the concentration and volume of diluted solution.

We are given:

Putting values in equation 1, we get:

Hence, the volume of stock solution needed is 62.5 mL

"standard molar enthalpy:

h2o ( liquid water ) : - 285.8 kj/mole

h2o ( water vapor ) : - 241.8 kj / mole.

δhrxn = - 241. 8 - ( - 285.8 )= -241.8 + 285.8 = 44.0

answer: 44.0 kj"