Question

Mass of empty flask (9) Mass of flask + KHP (9) Mass of KHP (g) TRIAL 1 L TRIAL 2 TRIAL 3 94.560g 89.0050 89 7357 94.9109 89.353 : 90.0949 0.250 0.3489 0.3499 0.00171 mol 0.00170.10 0.00171 wol 10.60 mL 0.83 L 60.50mL 10.83 mL 60.50 ML 124-80 with Moles of KHP Initial buret reading (mL) Final buret reading (mL) Volume NaOH solution used (ml) Moles of NaOH used Molarity NaOH Average Molarity of NaOH 0.00171md 0.00170 ud 0.0017 md

Answer 1

trial 1:
Volume of NaOH = final buret reading - initial buret reading
= 0.83 - 0.61 ml = 0.22 ml

moles of NaOH used = 0.00171 mole

Molarity of NaOH = moles of NaOH / Volume of NaOH used (in ml)
= 0.00171 * 1000 / 0.22 mol L^-1
= 7.77 M

trial 2 :
Volume of NaOH = 60.5 - 0.83 ml
= 59.67 ml

moles of NaOH = 0.00170 mol

Molarity of NaOH = moles of NaOH / Volume of NaOH used (in ml)
= 0.00170 * 1000 / 59.67 molL^-1
= 0.285M

trial 3: 60.5 is similar to the 0.00 ml of NaOH(because i think u fill the buret again).
Volume of NaOH = 24.8 - 0.00
= 24.8 ml

moles of NaOH = 0.00171 mol

Molarity of NaOH = moles of NaOH / Volume of NaOH used (in ml)
= 0.00171 * 1000 / 24.8 mol L^-1
= 0.069 M
Average molarity of NaOH = 7.77 + 0.285 + 0.069 /3
= 2.71M