What is the formula of the precipitate formed from the precipitation reaction of Pb(NO3)2 and NaI?
QUESTION 2
When aqueous solutions of (NH4)3PO4 and KOH are mixed, what precipitate(s) will form?
K3PO4
NH4OH
no precipitate will form
NH4OH and K3PO4
To determine the formula of the precipitate formed in a precipitation reaction, we need to find the chemical equation for the reaction and identify the products. Here's how you can find the formula of the precipitate formed from the precipitation reaction of Pb(NO3)2 and NaI:
1. Write the chemical equation for the reaction:
Pb(NO3)2 + 2NaI -> PbI2 + 2NaNO3
2. Balance the equation if necessary:
Pb(NO3)2 + 2NaI -> PbI2 + 2NaNO3
3. Identify the products of the reaction:
The products are PbI2 (lead(II) iodide) and NaNO3 (sodium nitrate).
4. Determine the formula of the precipitate:
The formula of the precipitate formed is PbI2, which is lead(II) iodide.
Now let's move on to the second question:
To determine the precipitate(s) formed when aqueous solutions of (NH4)3PO4 and KOH are mixed, we need to find the chemical equation and identify the products:
1. Write the chemical equation for the reaction:
(NH4)3PO4 + KOH -> K3PO4 + NH4OH
2. Balance the equation if necessary:
(NH4)3PO4 + 3KOH -> K3PO4 + 3NH4OH
3. Identify the products of the reaction:
The products are K3PO4 (potassium phosphate) and NH4OH (ammonium hydroxide).
4. Determine the precipitate(s):
In this reaction, no precipitate will form. The products are both aqueous, meaning they are dissolved in water and will not form a solid precipitate.
Therefore, in the reaction of (NH4)3PO4 and KOH, no precipitate will form.
For the precipitation reaction between Pb(NO3)2 and NaI, the formula of the precipitate formed can be determined by considering the solubility rules. Lead(II) iodide (PbI2) is insoluble, so it will be the precipitate formed. The balanced equation for the reaction is:
Pb(NO3)2 + 2NaI -> PbI2 + 2NaNO3
For the reaction between (NH4)3PO4 and KOH, you can determine the precipitate(s) formed by considering the solubility rules. Ammonium hydroxide (NH4OH) is slightly soluble, while potassium phosphate (K3PO4) is insoluble. Therefore, both NH4OH and K3PO4 will precipitate. The balanced equation for the reaction is:
3(NH4)3PO4 + 4KOH -> 3NH4OH + K3PO4
You need to know the solubility rules. Here is a set.
https://chem.libretexts.org/Core/Physical_and_Theoretical_Chemistry/Equilibria/Solubilty/Solubility_Rules