In: Chemistry
A 1.00 liter solution contains 0.39 M
ammonia and 0.30 M
ammonium nitrate.
If 0.15 moles of nitric acid are
added to this system,
indicate whether the following statements are TRUE
(T) or FALSE (F).
(Assume that the volume does not change upon the addition of
nitric acid.)
A. The number of moles of
NH3 will
increase.
B. The number of moles of
NH4+ will remain the
same.
C. The equilibrium concentration of
H3O+ will increase.
D. The pH will decrease.
E. The ratio of [NH3]
/ [NH4+] will remain
the same.
Answer – We are given, 0.39 M ammonia and 0.30 M ammonium nitrate
When new added strong acid in the base and its conjugate acid, then there is moles of base decrease and moles of conjugate acid increase. When we added strong acid it is reacted with base and formed the conjugate base, so moles of base consumed and decreased where conjugate base formed and moles of conjugate gets increased. So using these criteria the following statements where the true or false as follow -
A) The number of moles of NH3 will increase – False, since there is moles of base decrease.
B) The number of
moles of NH4+ will remain the same-
False, since there is conjugate acid moles
increase.
C) The equilibrium concentration of
H3O+ will Increase-True,
since there is addition of strong acid and there is increase the
moles of acid.
D) The pH will decrease – True,
since there is addition of strong acid and there is increase the
moles of acid and ratio of the acid by base gets increased and the
pOh gets more and pH decreased.
E) The ratio of [NH3] /
[NH4+] will remain the same –
False, since there is change in the moles of conjugate
base and base and due to that change in molarity and also change in
ratio.