Question

A buret containing NaOH solution has an initial volume reading of 0.14 mL.

25.00 mL of 0.1000 M HCl is titrated to a phenolphthalein end point, which occurs at a final reading of 27.16 mL NaOH. What is the molarity of the NaOH titrant?

Answer 1

IF molarity is in mol/dm3 then
Number of moles of HCL = 25/1000 x 0.1000=0.0025moles
Number of moles of NaOH= 0.0025 moles As 1 is to 1 ratio among them as from equation
NaOH+HCL=NaCL+H20
Volume of NaOH used=27.16-0.14 ml=27.02ml
moles=volume x molarity
0.0025=27.02/1000 x molarity
ANSWER molarity of NaOH=0.0925 mol/dm3

Answer 2

0.092 M

Step-by-step explanation:

NaOH(aq) + HCl(aq) ------> NaCl(aq) + H2O(l)

CA= concentration of acid= 0.1000 M

CB= concentration of base= ?????

VA= volume of acid= 25.00 mL

VB= volume of base= 27.16 mL

NA= number of moles of acid= 1

NB= number of moles of base= 1

CAVA/CBVB= nA/nB

CB= CAVAnB/VBnA

CB= 0.1000 M × 25.00 mL ×1/27.16 mL ×1

CB= 0.092 M