Answer : The mass of potassium phosphate needed will be 3.98 grams.
Explanation : Given,
Molarity of potassium phosphate = 0.75 M = 0.75 mole/L
Molar mass of potassium phosphate = 212.27 g/mole
Volume of solution = 25.0 mL = 0.025 L (conversion used : 1 L = 1000 mL)
Molarity : It is defined as the number of moles of solute present in one liter of solution.
In this problem solute is, potassium phosphate.
Formula used :
[tex]\text{Molarity}=\frac{\text{Mass of solute}}{\text{Molar mass of solute}\times \text{volume of solution in liter}}[/tex]
Now put all the given values in this formula, we get:
[tex]0.75mol/L=\frac{\text{Mass of solute}}{212.27g/mole\times 0.025L}[/tex]
[tex]\text{Mass of solute}=3.98g[/tex]
Therefore, the mass of potassium phosphate needed will be 3.98 grams.
