Question

1. A flask contains 4.00 g of solid sodium hydroxide. Some water is added to the flask to dissolve the sodium hydroxide, and enough water is added to fill the flask to a volume of 50.0 mL. What volume of 1.00 M HCl is needed to neutralize the sodium hydroxide?

A. 50.0 mL

B. 100.0 mL

C. 200.0 mL

2. A beaker contains 100.0 mL of a 0.100 M solution of sulfuric acid. When 100.0 mL water is added to this solution, what is the concentration of the diluted sulfuric acid?

A. 0.0250 M

B. 0.0500 M

C. 0.200 M

3. How many moles of NaOH are required to react completely with 1.00 mole of nitric acid?

A. 1.00 mol

B. 0.500 mol

C. 2.000 mol

Please explain. Thank you!

Answer 1

1. Neutralization implies that the moles of base are equal to the moles of acid, and thus they "cancel" each other by reacting to form water.

\(OH^-+H^+\rightleftharpoons H_2O \)

You need to find the moles of NaOH, these will be the moles of HCl you need. Then just find the volume of HCl solution needed.

Answer 2

@aaronq I found the moles of NaOH to be 39.997 g/mol

Answer 3

The molar mass of HCl is 36.46094 g/mol, I am not sure what to do for number 3.

Answer 4

that's the molar mass not the moles

Answer 5

\(\sf moles=\dfrac{mass}{Molar~mass}\)

Answer 6

Ok so I have the molar mass, moles = mass / 39.997? How do I find the moles, is that the "1.00 mole"?

Answer 7

So the moles of NaOH are 0.1 moles

\(\sf moles =\dfrac{ 4 g}{39.997 g/mol}\)

Answer 8

Now we know that they react in a 1:1 ratio (you would have to write the equation for the reaction and balance it).

So the moles of NaOH = moles of HCl

Now to find the volume of HCl

Answer 9

4/39.337=0.1000

Answer 10

Is there a formula I use to find the volume of HCI

Answer 11

the molarity formula, since those are the units the concentration of the solution is in

\(\sf Molarity=\dfrac{moles~of~solute}{L~of ~solution}\)

Answer 12

gtg