The nitrite ion has one less oxygen than the nitrate ion. Nitrate is NO3-1 while the nitrite ion is NO2-.
The pH of pure water is neutral because the concentration of hydronium ions equals that of hydroxide ions.
Answer: Option A
<u>Explanation:</u>
Water is one of the most important constituents of living being. It is said that there is no life without water. So that water need to neutral in nature to save life. Pure water is composed of hydronium 
and hydroxide 
ions. It is known that hydronium ions are acidic in nature with concentration of 
.
Similarly, the hydroxide ions which are basic in nature will be in same concentration as that of hydronium ions. So, as the concentration of basic and acidic elements are equal with the same strength of pH, the combination of these ions lead to formation of pure water with the pH being neutral.
Answer:
The precipitate is CuS.
Sulfide will precipitate at [S2-]= 3.61*10^-35 M
Explanation:
<u>Step 1: </u>Data given
The solution contains 0.036 M Cu2+ and 0.044 M Fe2+
Ksp (CuS) = 1.3 × 10-36
Ksp (FeS) = 6.3 × 10-18
Step 2: Calculate precipitate
CuS → Cu^2+ + S^2- Ksp= 1.3*10^-36
FeS → Fe^2+ + S^2- Ksp= 6.3*10^-18
Calculate the minimum of amount needed to form precipitates:
Q=Ksp
<u>For copper</u> we have: Ksp=[Cu2+]*[S2-]
Ksp (CuS) = 1.3*10^-36 = 0.036M *[S2-]
[S2-]= 3.61*10^-35 M
<u>For Iron</u> we have: Ksp=[Fe2+]*[S2-]
Ksp(FeS) = 6.3*10^-18 = 0.044M*[S2-]
[S2-]= 1.43*10^-16 M
CuS will form precipitates before FeS., because only 3.61*10^-35 M Sulfur Ions are needed for CuS. For FeS we need 1.43*10^-16 M Sulfur Ions which is much larger.
The precipitate is CuS.
Sulfide will precipitate at [S2-]= 3.61*10^-35 M
