Last modified: Wed 12/31/1969 06:00:00 pm
BCE

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Answer all of the questions below. If you do not know an answer enter CNA. However, it will help me the most if you answer each question with your best intuition/idea about what would be a reasonable answer.

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Our discussion of acids and bases has prepared you to calculate the pH of the following solutions,

strong acids
weak acids
strong bases
weak bases
the salt of a strong acid and a strong base
the salt of a strong acid and a weak base
the salt of aweak acid and a strong base
common ion - weak acid and its conjugate base
common ion - weak base and its conjugate acid

Our next system to consider in aqueous equilibria is the neutralization reaction. Lets look at a neutralization reaction in the context of the different types of acids and bases.

1. Predict the products of the following neutralization reactions:

a) NaOH(aq) + HNO3(aq) ---->

b) KOH(aq) + HCN(aq) ---->

c) NH3 (aq) + HCl(aq) ---->

2. Let get more quantitative with the first neutralization reaction. NOTE: This is solution stoichiometry calculations from CHEM 1314 so watch out! Suppose you are doing a titration (laboratory last week) to determine the concentration of a standardized solution of NaOH. Here is the following data that you collect in the experiment. (NOTE: The endpoint of a titration is when the mol of acid = mol of base)

Volume of standard NaOH solution : 15.00 mL

Concentration of HNO3 : 0.424 M

Volume of HNO3 solution required to reach the endpoint of the titration : 10.00 mL

a) how many mol of HNO3 reacted?

mol HNO3

b) how many mol of NaOH reacted?

mol NaOH

c) concentration of the standard NaOH solution?

M NaOH

3. Lets consider a titration where the concentration of NaOH is 0.283 M. In the titration the NaOH is added to a 25.0 mL sample of a 0.424 M HNO3 solution.

a) Calculate the pH of the HNO3 solution before any base is added.

pH =

b) If 5.00 mL of 0.283 M NaOH is added to the 25.0 mL sample of 0.424 M HNO3 answer the following questions:

i) How many mol of NaOH have been added when 5.00 mLs of 0.283 M NaOH are added to the acid solution?

mol of NaOH added mol

ii) How many mol of HNO3 would react?

mol of HNO3 reacting mol

iii) How many mol of HNO3 remain unreated?

mol of HNO3 remaining mol

iv) What is the new concentration of HNO3 after addition of NaOH

new [HNO3] M

v) What is the new pH of the solution

pH =

4. Is there anything about the questions that you feel you do not understand? List your concerns/questions.

5. If there is one question you would like to have answered in lecture, what would that question be?