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# Molar Solutions - NaOH

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The formula weight of NaOH is 40.0.

1. How many grams of NaOH are needed to make 1M solution?
2. How many grams of NaOH are needed to make a 0.5M solution?
3. How many grams of NaOH are needed to make 0.25M solution?
4. How many grams of NaOH are needed to make 500mL of 1.0M solution?
5. How many grams of NaOH are needed to make 100mL of 1.0M solution?
6. How many grams of NaOH are needed to make 10mL of 0.2M solution?

https://brainmass.com/chemistry/stoichiometry/molar-solutions-naoh-500034

## SOLUTION This solution is FREE courtesy of BrainMass!

Steps in finding the mass of solute needed to prepare a solution of certain molarity:

a) Solve for the mole of solute needed.
The following working equation is useful:
Molarity = M = mole solute / volume of solution in liter

Hence,
Mole solute = Molarity x volume of solution in liter

b) Compute for the mass in gram of the solute needed.
Mass of solute in gram = mole solute x molar mass of the solute

1. How many grams of NaOH are needed to make 1M solution?
Note: Since the volume of the solution to be prepared is not specified, let us assume a volume of 100 mL. In case a different volume is required, just substitute accordingly in the following computation.

1 mol/L = mole NaOH / 0.1 L

mole NaOH = (1 mol/L)(0.1L)
mole NaOH = 0.1

Mass of NaOH = 0.1 mole x 40 g/mole
Mass of NaOH = 4.0 g

2. How many grams of NaOH are needed to make a 0.5M solution?
Note: Since the volume of the solution to be prepared is not specified, let us assume a volume of 100 mL. In case a different volume is required, just please substitute accordingly in the following computation.

0.5 mol/L = mole NaOH / 0.1 L

mole NaOH = (0.5 mol/L)(0.1L)
mole NaOH = 0.05

Mass of NaOH = 0.05 mole x 40 g/mole
Mass of NaOH = 2.0 g

3. How many grams of NaOH are needed to make 0.25M solution?
Note: Since the volume of the solution to be prepared is not specified, let us assume a volume of 100 mL. In case a different volume is required, just please substitute accordingly in the following computation.

0.25 mol/L = mole NaOH / 0.1 L

mole NaOH = (0.25 mol/L)(0.1L)
mole NaOH = 0.025

Mass of NaOH = 0.025 mole x 40 g/mole
Mass of NaOH = 1.0 g

4. How many grams of NaOH are needed to make 500mL of 1.0M solution?

1.0 mol/L = mole NaOH / 0.5 L
mole NaOH = (1 mol/L)(0.5L)
mole NaOH = 0.5

Mass of NaOH = 0.5 mole x 40 g/mole
Mass of NaOH = 20.0 g

5. How many grams of NaOH are needed to make 100mL of 1.0M solution?

1.0 mol/L = mole NaOH / 0.1 L
mole NaOH = (1 mol/L)(0.1L)
mole NaOH = 0.1

Mass of NaOH = 0.1 mole x 40 g/mole
Mass of NaOH = 4.0 g

6. How many grams of NaOH are needed to make 10mL of 0.2M solution?

0.2 mol/L = mole NaOH / 0.01 L
mole NaOH = (0.2 mol/L)(0.01L)
mole NaOH = 0.002

Mass of NaOH = 0.002 mole x 40 g/mole
Mass of NaOH = 0.08 g.

This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!