Predict whether the following solutions are acidic, basic, or nearly neutral:
a. NaBr,
b. K2SO3,
c. NH4NO2,
d. Cr(NO3).
the answer is neutral, basic, acidic, acidic and i am not sure why
Look to see what the hydrolysis products would be. For example, IF Na^+ and Br^- hydrolyzed, they would produce NaOH and HBr but NaOH is a strong base and HBr is a strong acid; therefore, neither hydrolyze. Thus, neutral.
K2SO3. If K^+ and SO3^- hydrolyze, they produce KOH and H2SO3. You know KOH is a strong base. K^+ doesn't hydrolyze. H2SO3 is a weak acid, the SO3^- DOES hydrolyze, and K2SO3 is basic (strong base/weak acid gives basic soln).
I would have classified NH4NO2 as nearly neutral (apparently that was one of the choices) since NH3 and HNO2 are weak base/weak acid. The pH is 6.27 which is almost neutral.
a. NaBr - nearly neutral
b. K2SO3 - basic
c. NH4NO2 - acidic
d. Cr(NO3)3 - acidic
acide
To predict whether a solution is acidic, basic, or nearly neutral, we need to consider the nature of the ions present in the solution.
a. NaBr:
When NaBr dissolves in water, it dissociates into Na+ and Br- ions. Na+ is derived from a strong base (NaOH) and is not acidic or basic. Br- is derived from a strong acid (HBr) and is also not acidic or basic. Therefore, NaBr solution is nearly neutral.
b. K2SO3:
When K2SO3 dissolves in water, it dissociates into 2K+ and SO3^2- ions. K+ is derived from a strong base (KOH) and is not acidic or basic. SO3^2- is derived from a weak acid (SO2) and is considered weakly basic. Therefore, K2SO3 solution is basic.
c. NH4NO2:
When NH4NO2 dissolves in water, it dissociates into NH4+ and NO2- ions. NH4+ is derived from a weak base (NH3) and is considered weakly acidic. NO2- is derived from a weak acid (HNO2) and is also considered weakly acidic. Therefore, NH4NO2 solution is expected to be acidic.
d. Cr(NO3)3:
Chromium (III) nitrate, Cr(NO3)3, dissociates into Cr^3+ and NO3- ions when dissolved in water. Cr^3+ is derived from a weak base (Cr(OH)3) and is considered weakly acidic. NO3- is derived from a strong acid (HNO3) and is not acidic or basic. Therefore, Cr(NO3)3 solution is expected to be acidic.
In conclusion:
a. NaBr is nearly neutral.
b. K2SO3 is basic.
c. NH4NO2 is acidic.
d. Cr(NO3)3 is acidic.