Determine the concentration of NO3- in each of the following aqueous solutions. (Assume complete dissociation of each compound.) 0.30 M KNO3, 0.30 M Ca(NO3)2, 0.30 M Cr(NO3)3
Boy, am I out of it! I did not know that what we used to call chemistry is now called Moorpark! Thanks for cluing me in.
To determine the concentration of NO3- in each aqueous solution, we need to take into account the dissociation of the compounds in water.
1. 0.30 M KNO3:
KNO3 dissociates into K+ and NO3-. Since KNO3 is a strong electrolyte, it completely dissociates. Therefore, the concentration of NO3- is also 0.30 M.
2. 0.30 M Ca(NO3)2:
Ca(NO3)2 dissociates into Ca2+ and 2NO3-. Again, since Ca(NO3)2 is a strong electrolyte, it completely dissociates. So, the concentration of NO3- ions is twice the concentration of the compound. Therefore, the concentration of NO3- is 2 x 0.30 M = 0.60 M.
3. 0.30 M Cr(NO3)3:
Cr(NO3)3 dissociates into Cr3+ and 3NO3-. As before, since Cr(NO3)3 is a strong electrolyte, it fully dissociates. Thus, the concentration of NO3- is three times the concentration of the compound. Therefore, the concentration of NO3- is 3 x 0.30 M = 0.90 M.
In summary:
- In 0.30 M KNO3, the concentration of NO3- is 0.30 M.
- In 0.30 M Ca(NO3)2, the concentration of NO3- is 0.60 M.
- In 0.30 M Cr(NO3)3, the concentration of NO3- is 0.90 M.