Use the periodic table to answer the question.

Question

An illustration shows the periodic table of elements with elements arranged in increasing order of atomic number in 18 columns (groups) and 7 rows (periods). The electronegativity of elements increases from left to right, across a period. The hydrogen on the left is included in group with medium electronegativity. Also, fluorine is shown as element with highest electronegativity.

Based on patterns in the periodic table, which list shows the acids in order from strongest to weakest?

(1 point)
Responses

H2S, PH3, HCl
H 2 S, PH 3 , HCl

HCl, H2S, PH3
HCl, H 2 S, PH 3

HCl, PH3, H2S
HCl, PH 3 , H 2 S

PH3, H2S, HCl

Answer 1

To determine the order of acidity from strongest to weakest among the acids HCl, H2S, and PH3, we can evaluate their structures and the electronegativities of the elements involved.

1. HCl (Hydrochloric acid) - The bond between hydrogen and chlorine is a strong bond due to chlorine's high electronegativity. This makes HCl a strong acid as it dissociates completely in water.

2. H2S (Hydrosulfuric acid) - Sulfur has a lower electronegativity than chlorine but is still capable of forming a weak acid. H2S is more acidic than PH3, but less acidic than HCl.

3. PH3 (Phosphine) - Phosphorus has low electronegativity and does not easily donate a proton compared to the other two. Therefore, PH3 is the weakest among these three compounds.

Based on this analysis, the order from strongest to weakest acid is:

HCl > H2S > PH3

Thus, the correct choice is:

HCl, H2S, PH3.