Description
A 10.0-mL sample of pineapple juice was titrated with 0.100 M sodium hydroxide solution. the average volume of NaOH required to reach the endpoint was 12.8 mL
a.Calculate the number of moles of sodium hydroxide required to reach the endpoint
answer:
b.Using the mole ratio for the neutralization reaction shown in equation 1, determine the number of moles of citric acid in 10.0 mL of the of pineapple juice.
Explanation & Answer
DATA:
Volume of citric acid= 10.0mL
Concentration of NAOH= 0.1M
Volume of NaOH= 12.8mL
Moles of NaOH at end point= ?
Moles of citric acid/10.0mL= ?
SOLUTION:
C6H8O7 + 3NaOH è Na3C6H5O7 + 3H2O
MOLES OF NaOH:
1000.0mL of NaOH contains 0.1 mol Of NaOH
12.8mL of NaOH contains (0.1*12.8)/1000
=1.28*10-3 mol of NaOH
MOLES OF CITRIC ACID:
3NaOH = 1 C6H8O7
1.28*10-3 = (1*1.28*10-3)/3
= 4.2666*10-4 mol of C6H8O7/10.0mL
ANSWER:
Moles of NaOH at end point= 1.28*10-3 mol of NaOH
Moles of citric acid/10.0mL=4.2666*10-4 mol of C6H8O7