You are tasked with preparing a 500mL nutrient solution containing 5mg/L of phosphorous

(P), 3mg/L nitrate (NO3
-) and 100 mg/L chloride (Cl-). To make this solution, you have
powdered sodium chloride, a 100 mg/L solution of phosphorus, a 1000 mg/L of sodium nitrate
(NaNO3) and water. Based on the final solution:
a. How many milligrams of sodium chloride is required?
b. What volume (in mL) of the 100 mg/L phosphorus solution is required?
c. What is the final concentration of sodium?

Any help is appreciated. Thank you!

2 answers

For a,how much NaCl is needed?
100 mg/L is what you want, and you want 500 mL; therefore, you need 100 mg/L x 0.500 L = ? mg.

For b,
You want 500 mL of 5 mg/L; therefore, you need 5 mg/L x 0.5L = 2.5 mg P.
You have 100 mg/L solution, how much of that do you need?
100 mg/L x ?L = 2.5
Solve for L and convert to mL. I'll leave c for you. Same process but you must find NO3^- and add Na from that to Na from NaCl. Find total Na and final volume is 500 mL.
Thank you for your help!
For part c, I'm not sure what you mean finding Na from NO3^-?