Question

Use the periodic table to answer the question.

Periodic table showing electronegativity of elements, increasing left to right and bottom to top.

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

(1 point)
Responses

PH3, H2S, HCl
PH3, H2S, HCl

HCl, H2S, PH3
HCl, H2S, PH3

H2S, PH3, HCl
H2S, PH3, HCl

HCl, PH3, H2S

Answer 1

To determine the strength of the acids in the list, we should consider the electronegativity of the atoms involved. In general, acids are stronger when the hydrogen is bonded to a more electronegative atom because this bond is more polar, making it easier to release a proton (H⁺).

1. **HCl**: Chlorine (Cl) is highly electronegative, so HCl is a strong acid.
2. **H2S**: Sulfur (S) is less electronegative than chlorine, making H2S a weaker acid than HCl.
3. **PH3**: Phosphorus (P) is even less electronegative, making PH3 a weak acid compared to both HCl and H2S.

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

**HCl, H2S, PH3**

So, the correct response is:

**HCl, H2S, PH3**.