A 2.00% NaOH solution by mass has a density of 1.054 g/mL. What is the minimum molarity of an HCl(aq) solution

Question

A 2.00% NaOH solution by mass has a density of 1.054 g/mL. What is the minimum molarity of an HCl(aq) solution that can be used to titrate a 4.00 mL sample of the NaOH(aq) if the titration is to be accomplished without having to refill a 50.00 mL buret used in the titration?

Answer 1

Consider one liter of this 2.00% NaOH solution. The mass must be 1054g. 2.00% NaOH results in 21.08g of NaOH, or 0.527M. hence:
0.00400*0.527 = 0.05000*[HCl]
The minimum molarity of an HCl(aq) solution is:
[HCl] = 0.00400*0.527 /0.05000 = 0.0422(M)

Answer 2

Mass 28 g density= .90 g/mL density=mass/volume or, volume=mass/density=28g/0.90g/ml =31.11ml no. of mole=31.11/mw of Nh3 =31.11/17 = 1.83M molarity of solution= 1.83M/l ( 1litre solution) M=mole/volume