Question

question 33 of 37
for the list of compounds, rank the compounds in strength from weakest acid to strongest acid.
weakest
strongest
answer bank
nh₃ sbh₃ ph₃ ash₃

Explanation:

For hydrides of group 15 elements, acid strength increases down the group. This is because as the atomic size of the central atom increases, the bond strength between the central atom and hydrogen decreases, making it easier to release H⁺ ions. Nitrogen is the smallest in the group, so NH₃ has the strongest N-H bond and is the weakest acid. Antimony is the largest in the given set, so SbH₃ has the weakest Sb-H bond and is the strongest acid.

Answer:

Weakest: $\ce{NH3}$
$\ce{PH3}$
$\ce{AsH3}$
Strongest: $\ce{SbH3}$