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# How do you prepare 0.5 N NaOH solution?

Updated: 8/10/2023 Wiki User

11y ago

There is 0.5 moles of NaOH per litre To calculate 0.5 molar NaOH first know the molecular weight of NaOH i.e 40 now multiply the number of moles of NaOH you have (0.5) found as above. so to find the number of grams of NaOH we needed to start with (0.5) * (40) = 20g So dissolve 20g of NaOH in one litre of the solution to prepare 0.5 molar solution Wiki User

15y ago  Study guides

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1447 Reviews Wiki User

11y ago

Molar mass of NaOH is roughly 40 g/mol. That is solution is 1N NaOH when 40g NaOH is dissolved in 1L water. Here, molarity and normality will be same.

For our purpose, weigh 20g of NaOH and dissolve it in 500ml water. At this point, the solution is 1N NaOH. Dilute this solution to 1000ml. Stir well. You have 0.5N NaOH solution. Done.   Wiki User

13y ago

50 mM NaOH solution means that there are .050 moles of NaOH for each liter or solution. Likewise for 5 M meaning 5 moles per liter. So,

5 moles/liter * 1 liter = 5 moles.

So you have 5 total moles of NaOH. You want to use that to make a 50 mM solution.

In order to dilute 5 moles/liter down to .050 moles/liter, you have to add water.

For example, if you only want 1 liter of the final .050 M solution, then you only need .050 moles of NaOH.

So you take the 5M solution and find out how much contains .050 moles of NaOH.

5 moles/liter * x liters = .050 Moles

.050 Moles / 5 moles/liter = .01 liters.

So .01 Liters, or 10 milliliters of the 5 M solution, combined with 990 milliliters of water makes 1 liter of .050 M solution.   Wiki User

13y ago

The molarity is figured out by the number of moles of NaOH over the number of liters of water. so if the molarity is 0.5M and there is 1.0L of water then there has to be 0.5 moles of NaOH in the solution.   Wiki User

10y ago

Mol.wt of NAOH= 40

Molarity= amount of solute in g/l of solution/ molw.t

0.5M= g/L / 40

g/l = 0.5 * 40

= 20g

1ml contains 20 g per 1000 ml so

50ml contains= 20/1000* 50 =1g   Wiki User

6y ago

Typically, this problem means 5% mass/volume which is 5 g NaOH/100 ml solution. This translates into 5 g x 1 mole/40 g = 0.125 moles NaOH/100 ml = 0.125/0.1 L = 1.25 M

If the problem is actually 5 percent mass/mass NaOH, then you have 5 g NaOH/100 g solution. If the masses are additive, that means 95 g H2O (or 95 ml H2O if the density is 1 g/ml). If these assumptions are correct, then you have 5 g NaOH/95 ml H2O. 5 g NaOH x 1 mol/40 g = 0.125 moles NaOH
0.125 moles/0.095 L = 1.32 M   Wiki User

13y ago

C1 x V1 = C2 x V2 (concentration1)(volume1) = (concentration2)(volume2)

15M(V1) = 5M(V2)

Since you aren't given a volume, its a 3-fold dilution   Wiki User

12y ago

O (Oxygen) has a molar mass of 16.00g. Na (Sodium) has a molar mass of 22.99g. H (Hydrogen) has a molar mass of 1.01g.

Therefore the molar mass of NaOH (Sodium Hydroxide) is 40.00g.   Wiki User

13y ago

It depends on how much water you're using.

Since NaOH has a molar mass of 40g/mol, you would use 20 grams of NaOH for every liter of water.   Wiki User

6y ago

The molar mass of NaOH is 40 g/mole0.5 millimolar (mM) is 0.5 millimoles/liter

To make 1 liter of 0.5 mM you need 0.5 mmol/L x 40 mg/mmole = 20 mg in 1 liter of solution   Earn +20 pts  