Hey guys, I am doing a lab right now and I am totally screwed. I need an 8 on this lab or I am going to fail the course!! I've never got more than a 6.7 from my teacher so I really need a hero!
We took lemon juice and put NaOH in with it and an indicator that made it go pink after average 4.37 mL of NaOH put in. It is 1.000 M NaOH.
Lemon Juice pH reading was 2.40
Tap water pH after 4 x 30 sec. of blowing through it with a straw was 6.12
1) "Write the balanced equation for the neutralization of citric acid using NaOH solution."
2) "What is the stoichiometric ratio between citric acid and NaOH"
3) "Calculate H+ molarity, [H+] in mol/L in the lemon juice based on the average titration volume and the stated molarity of the NaOH solution"
4)" Use the stoichiometric ratio to calculate the citric acid molarity (moles/Liter) of the lemon juice."
Guidelines for Discussion:
1. What should the pH of a pure sample of distilled, deionized water be?
2. Based on its measured pH, which of the following best describes the chemical nature of Sarnia tap- water? (pH is 7.23)
(a) acidic,
(b) slightly acidic
© neutral
(d) slightly basic
(e) basic
3. Name and write the formula of the chemical compound in Sarnia tap-water that is
causing the characteristic described in question 2. ?
4. Name and write the formula of the component of exhaled air that causes the pH of tap-water to decrease?
5. Write the chemical equation for the change mentioned in 4.
4. Write the formula of the gaseous chemical released by coal-fired generating stations and internal combustion engines that is primarily responsible for acid rain?
5. Convert the measured pH of the lemon juice into H+ molarity [H+] in mol/L
6. Compare the [H+] calculated in 5. with the [H+] determined on page 1. based on the titration?
Bonus
7. Show how the weak acid behaviour of citric acid can be used to explain the difference between the two H+ molarities stated in 6
