CHEMISTRY

To prepare 30.0mL of 0.800M HNO3 from a stock solution of 4.00M HNO3, you will need to use 24.0 mL of the 4.00M HNO3 stock solution. First, calculate the volume of the solute needed to make 30.0mL of 0.800M HNO3:

Molarity = Moles of solute/Liters of solution

0.800 M = (x moles of solute)/(0.030 L)

x moles of solute = 0.800 M x 0.030 L = 0.024 moles of solute

Now calculate the volume of the 4.00M HNO3 stock solution needed:

Molarity = Moles of solute/Liters of solution

4.00M = (0.024 moles of solute)/(x L of stock solution)

x L of stock solution = 0.024 moles of solute/4.00M = 0.024/4.00 = 0.06 L = 60.0 mL

Thus, you will need to use 24.0 mL of the 4.00M HNO3 stock solution to prepare 30.0mL of 0.800M HNO3.