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1) The substance diethylamine is a weak nitrogenous base like ammonia. Write a n

ID: 995923 • Letter: 1

Question

1) The substance diethylamine is a weak nitrogenous base like ammonia.

Write a net ionic equation to show how diethylamine, (C2H5)2NH, behaves as a base in water. state is its s/l/g/aq.

2) The substance trimethylamine is a weak nitrogenous base like ammonia.

Complete the following equation that shows how trimethylamine reacts when dissolved in water.


?

3)

Which of the following aqueous solutions are buffer solutions ?
.

0.33 M NH4NO3 + 0.40 M NH3
.

0.13 M HCN + 0.11 M KCN
.

0.25 M HBr + 0.20 M KBr
.

0.34 M CH3COOH + 0.23 M CH3COOK
.

0.16 M KOH + 0.24 M KBr
4)

Which of the following aqueous solutions are buffer solutions ?
.

0.29 M NH4Br + 0.35 M NH3
.

0.18 M NaOH + 0.26 M NaCl
.

0.27 M HNO3 + 0.19 M KNO3
.

0.40 M NaBr + 0.28 M NaNO3
.

0.10 M HF + 0.16 M KF
5)

+ ? +

?

Explanation / Answer

1) (C2H5)2NH + H2O ----------->  (C2H5)2NH2+ + OH-

2) (CH3)3N + H2O ------------> (CH3)3NH+ + OH-

3) Buffer solution = weak acid and its salt with strong base

Buffer solution = weak base and its salt with strong acid

  0.33 M NH4NO3 + 0.40 M NH3, 0.13 M HCN + 0.11 M KCN, 0.34 M CH3COOH + 0.23 M CH3COOK

  are buffer solutions .

Because, NH3 is a weak base and HCN,CH3COOH are weak acids.

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0.25 M HBr + 0.20 M KBr , 0.16 M KOH + 0.24 M KBr are not buffer solutions because HBr is a strong acid and KOH is a strong base.

4)

0.29 M NH4Br + 0.35 M NH3 , 0.10 M HF + 0.16 M KF are buffer solutions because NH3 is a weak base and HF is a weak acid.

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0.18 M NaOH + 0.26 M NaCl , 0.27 M HNO3 + 0.19 M KNO3, 0.40 M NaBr + 0.28 M NaNO3

are not buffer solutions because NaOH is a strong base and HNO3 is a strong acid.