Zadania z chemii IB HL

Znalezionych zadań: 4

Filtry i umiejętności1

A buffer solution can be prepared by mixing $\ce{NH3(aq)}$

with

\ce{HCl(aq)}

. (i) Describe how the two solutions should be combined so that the buffer obtained is as effective as possible. (ii) Write equations to show how this buffer solution responds to the…

A buffer solution contains propanoic acid at 0.300 $\mathrm{mol\,dm^{-3}}$ and sodium propanoate at 0.600 $\mathrm{mol\,dm^{-3}}$ . What is its pH? p $K_\mathrm{a}$ (propanoic acid) = 4.87 A. 4.57 B. 4.87 C. 5.17 D. 5.47

Methanoic acid, $\ce{HCOOH}$ , is a weak acid, and solutions of it are often used as acidic buffers. A chemist prepared a $0.500\ \mathrm{mol\,dm^{-3}}$ solution of methanoic acid, in which two conjugate acid–base pairs are present. (i) For each pair, state the…

(i) Describe how aqueous hexanoic acid and aqueous sodium hydroxide could be used to make a buffer solution. (ii) Predict the effect on the buffer's pH of adding a small amount of water.