Strontium Nitrate and Ammonium Hydroxide Reaction: Formation of Precipitate

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In summary, the conversation discusses the combination of strontium nitrate and ammonium hydroxide, and the attempt to find a net ionic equation. It is noted that not all hydroxides are water-soluble, and the solubility figures for strontium hydroxide are given. The conversation also mentions a lab experiment where no precipitate was formed, and the estimation of the required concentration of strontium for a precipitate to form using ammonia. It is concluded that a strong base like NaOH or KOH is needed to see a precipitate.
  • #1
Sace Ver
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Homework Statement


Strontium Nitrate + Ammonium Hydroxide =

Homework Equations


Finding net ionic equation

The Attempt at a Solution


Balanced Equation:
Sr(NO3)2(aq) + NH4OH (aq) = Sr(OH)2(aq) + NH4NO3 there is no precipitate correct? I will not need to find the net-ionic equation.
 
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  • #2
Sace Ver said:

Homework Statement


Strontium Nitrate + Ammonium Hydroxide =

Homework Equations


Finding net ionic equation

The Attempt at a Solution


Balanced Equation:
Sr(NO3)2(aq) + NH4OH (aq) = Sr(OH)2(aq) + NH4NO3 there is no precipitate correct? I will not need to find the net-ionic equation.
Not all hydroxides are water-soluble:

https://en.wikipedia.org/wiki/Strontium_hydroxide
 
  • #4
Sace Ver said:
I was doing a lab today and no precipitate formed.
Well, it all depends on how much Sr hydroxide you made and how much water there is.

The solubility figures for Sr hydroxide are given in the Wiki article.

You can contrast those solubility figures with comparable ones for ammonium nitrate:

https://en.wikipedia.org/wiki/Ammonium_nitrate
 
  • #5
It is rather easy to estimate.

pH of a 1 M ammonia solution is around 11.2, so [OH-] = 4.2×10-3

Different sources list different values for solubility product of Sr(OH)2, but apparently it is around 10-4.

That means using 1 M ammonia you should not expect precipitate unless concentration of the Sr2+ is around 6 M.

Using more concentrated ammonia (3 M) will shift the required Sr2+ concentration down to 1.9 M, still quite high.

No wonder you couldn't see any precipitate. For that you would need a strong base like NaOH or KOH.
 

FAQ: Strontium Nitrate and Ammonium Hydroxide Reaction: Formation of Precipitate

1. What is a precipitate?

A precipitate is a solid substance that forms from a chemical reaction when two or more aqueous solutions are combined.

2. How do you know when a precipitate has formed?

You can tell a precipitate has formed when you see a cloudy or milky appearance in the solution, or when you observe solid particles settling at the bottom of the container.

3. What causes the formation of a precipitate?

The formation of a precipitate is caused by a chemical reaction between two or more solutions, resulting in the creation of a new solid substance that is insoluble in the solution.

4. Can a precipitate be reversed?

In most cases, a precipitate cannot be reversed. Once the solid substance has formed, it is difficult to dissolve it back into the solution. However, certain chemical reactions can be manipulated to reverse the formation of a precipitate.

5. What factors can affect the formation of a precipitate?

The formation of a precipitate can be affected by various factors such as temperature, concentration of solutions, and the presence of other substances that can react with the solutions. Additionally, the rate of stirring and the order of mixing the solutions can also impact the formation of a precipitate.

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