Which will make basic buffer?

Options

A. 50 mL of 0.1 M NaOH + 25 mL of 0.1 M `CH_3COOH`
B. 100 ml of 0.1 M `CH_3COOH` + 100 mL of 0.1 M NaOH
C. 100 mL of 0.1 M HCl + 200 mL of 0.1 M `NH_4OH`
D. 100 mL of 0.1 M HCl+ 100 mL of 0.1 M NaOH

Answer

C

Explanation

a. `CH_3COOH+NaOH rarr CH_3COONa+H_2O`
`{:("Initial", " "25 "mL", " "50 "mL" , 0),(,xx0.1 M , xx0.1 M, ),(,=2.5 "mmol",= 5 "mmol",),("Final"," " 0, " "2.5 "mmol" , 2.5 "mmol"):}`
This is basic solution due to NaOH.
This is not basic buffer.
b. `CH_3COOH+NaOH rarr CH_3COONa+H_2O`
`{:("Initial", " "100 "mL", " "100 "mL" , 0),(,xx0.1 M , xx0.1 M, ),(,=10 "mmol",= 10 "mmol",),("Final"," " 0, " "0, 10 "mmol"):}`
Hydrolysis of salt takes place.
This is not basic buffer.
c. `HCl+NH_4OH rarr NH_4Cl+H_2O`
`{:("Initial", " "100 "mL", " "200 "mL" , 0),(,xx0.1 M , xx0.1 M, ),(,=10 "mmol",= 20 "mmol",),("Final"," " 0, " "10 "mmol" , 10 "mmol"):}`
This will make basic buffer.
d. `HCl+NaOH rarr NaCl+H_2O`
`{:("Initial", " "100 "mL", " "100 "mL" , 0),(,xx0.1 M , xx0.1 M, ),(,=10 "mmol",= 10 "mmol",),("Final"," " 0, " "0 "mmol" , 10 "mmol"):}`
`implies` This is Neutral solution.