Question

How many mL of 7.73 M NaOH are needed to prepare 324 mL of 0.146 M NaOH?

Your Answer:

Question 5 options:

Answer	units

What is the molarity of a NaOH solution if 27.1 mL are needed to titrate a 0.6119 g sample of KHP?

Your Answer:

Question 6 options:

Answer	units

Answer 1

5)
Initially
Molarity (M1) = 0.146 M
Volume(V1) = 324 mL

Finally
Molarity (M2) = 7.73 M
Volume (V2) = ?

Now
M1V1 = M2V2
0.146 M * 324 mL = 7.73 M * V2
V2 =( 0.146 M * 324 mL) / 7.73 M
V2 = 6.12 mL
Volume become = 6.12 mL

6)

KHP mass = 0.6119 g
KHP molar mass = 204.22 g/mol
Number of moles of KHP = mass / molar mass
Number of moles of KHP = 0.6119 g / 204.22 g/ mol
Number of moles of KHP = 2.996*10^-3 mol
                
moles of KHP = moles of NaOH
Because the titration between these two 1:1

2.996x 10^-3 = moles of NaOH
Volume = 27.1 mL * 1 L/ 1000 mL = 0.0271 L
molarity of NaOH = moles of NaOH / volume (Litre)
molarity of NaOH= 2.996 x 10^-3 mol/ 0.0271 L
molarity of NaOH=0.116 M