Calculate the $pH$ of a buffer solution containing $0.04 \ M$ $NaF$ and $0.02 \ M$ $HF$ $[pK_a = 3.142]$.

Which of the following would produce a buffer solution when mixed in equal volumes?

Which one of the following is not a buffer solution?

Assertion : Buffer system of carbonic acid and sodium bicarbonate is used for the precipitation of hydroxides of third group elements.
Reason : It maintains the $pH$ to a constant value,about $7.4.$

Which of the following solutions will act as a buffer solution?

For preparing a buffer solution of $pH = 5$ by mixing sodium acetate and acetic acid,the ratio of the concentration of salt and acid should be $(K_a = 10^{-5})$:-