Question

1. Rank the following compounds in order of decreasing acid strength using periodic trends. Rank the acids from strongest to weakest. To rank items as equivalent, overlap them. A. HCl. B. H2S. C. HBr. D. BH3.2. Without consulting the table of acid-dissociation constants, match the following acids to the given Ka1 values.A. H2S. B. H2SO3. C. H2SO4.1. Kal = 1.7 x 10^-7.2. Kal = 1.7 x 10^-2.3. Kal = very large.

Answer 1

Answer:

1. HBr>HCl> H2S >BH3

2.K_a1 very large — H2SO4

K_a1= 1.7 x 10^−2 — H2SO3

K_a1 = 1.7 x 10^−7 — H2S

Explanation:

As one goes down a row in the Periodic Table the properties that determine the acid strength can be observed.

The atoms get larger in radius meaning that in strength, the strength of the bonds get weaker, conversely meaning that the acids get stronger.

For the halogen-containing acids above following the rows and periods, HBr has the strongest bond and is the strongest acid and others follow in this order.

HBr>HCl> H2S >BH3

Acid Dissociation Constant provides us with information known as the ionization constant which comes in handy to measure the acid's strength. The meaning of the proportions are thus, the higher the Ka value, the stronger the acid i.e. it liberates more number of hydrogen ions per mole of acid in solution.

In solution strong acids completely dissociate hence, the value of dissociation constant of strong acids is very high.

Following the cues above on Ka;

K_a1 very large — H2SO4

K_a1= 1.7 x 10^−2 — H2SO3

K_a1 = 1.7 x 10^−7 — H2S