Question

(1)Make 500 ML of 4N H3PO4. How many grams will be needed?

(2) In a titration procedure, 20mL of 2N solution were required to titrate 5mL of an unknown solution. What is the normality of the solution?

(3) How much of a 0.01M can be made from 20mL of 6M HCl?

(4)How many grams of NaOH are present in 300mL of a 6M solution of sodium hydroxide?

Answer 1

you want 2 mols (half a liter of 4N)

H3PO4 = 3+31+4(16) grams/mol

Answer 2

molarity=gramsSolute/(MolMass*Liters)

a) gramsSolute=Molarity*Molmass*Liters. I have no idea what ML means, do you mean millilters, or 1/2 Liter?

b) Normality=Heq*Molarity
VaNa=Vb*Nb
Nb=VaNa/Vb=.020*2/.005=8N

c. you are diluting it 6/.01 or 600 times, or 60O*20ml=18Liters

d. massSolute=Molarity/(volumeL*molmass)
= 6/(.3*40)

Answer 3

I think this question should be reviewed and/or rethought.
a. mL x N x milliequivalent weight = grams.
500 x 4 x (98/3000) = about 65 g.

b. 8N is right

c. There is a typo here. 600*20 = 12,000 mL or 12 L.

d. mols = M x L = 6 x 0.3 = 1.8 mols. Then grams = mols x molar mass = 1.8 x 40 = 72 g NaOH OR
g = M x L x molar mass = 6 x 0.3 x 40 = about 72 grams.