4.2.1 Precipitation Reactions Flashcards Preview

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Flashcards in 4.2.1 Precipitation Reactions Deck (12)
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1
Q

Precipitation Reactions

A
  • A precipitation reaction occurs when substances in solution react to form a solid insoluble salt.
  • A solubility table helps in predicting the solubility of a salt.
2
Q

precipitate

A
  • A precipitation reaction occurs when substances in solution react to form a solid insoluble salt. This salt is called a precipitate.
  • For example, when a solution of lead(II) nitrate (Pb(NO3)2) is mixed with a solution of potassium iodide (KI), a yellow precipitate forms. This precipitate is lead(II) iodide (PbI2). Since potassium ionand nitrate ion do not take part in the precipitation reaction, they are not shown in the net ionic equation. Ions which do not take part in a reaction are called spectator ions.
3
Q

example

A
  • A solubility table helps in predicting the solubility of a salt.
  • Problem: What is the precipitate when a solution of nickel(II) nitrate (Ni(NO3)2) is mixed with a solution of sodium carbonate (Na2CO3)?
  • First, identify the ions in the solution (Ni2+, NO3–, Na+, and CO32–).
  • Second, check a solubility table for information on these ions. Compounds containing alkali metal ions such as sodium ion (Na+) tend to be soluble, so sodium ion will not precipitate. Compounds containing nitrate ion (NO3-) also tend to be soluble, so nitrate ion will not precipitate.
  • However, compounds containing carbonate ion (CO32–) tend to be insoluble. Therefore, the precipitate is nickel(II) carbonate (NiCO3).
4
Q

The nitarate of an unknown cation is mixed with four different solutions. the results of these mixtures are shown below
Solution Result
NaCl no precipitate
Na2SO4 precipitate
NaOH no precipitate
Na2CO3 precipitate
Based on these results which of these is most likely the unknown cation

A

Ba2+

5
Q

Suppose you have a solution of K2SO4. If you want to separate the potassium and sulfate ions from each other, which of these should you add?

A

a solution of Pb(NO3 )2

6
Q

Which of the following compounds would you expect to be the most soluble?

A

sodium sulfate

7
Q

An ionic compound that contains lead is soluble in water. Of the four compounds listed, which should be the most soluble.

A

Pb(ClO3 )2

8
Q

The net ionic equation of a precipitation reaction is as follows.

2Al 3+ + 3CrO42− → Al2 (CrO4 )3 (s) 

Which of these pairs of solutions could have been combined to cause this reaction?

A

a solution of Al(NO2 )3 and a solution of K2CrO4

9
Q

A solution of barium nitrate (Ba(NO3 )2 ) is combined with a solution of copper(II) sulfate (CuSO4 ). What is the overall precipitation reaction that will occur?

A

Ba2+ + 2NO3− + Cu2+ + SO42− → BaSO4 (s) + 2NO3− + Cu2+

10
Q

Permanganate, a polyatomic ion, has the formula MnO4−. The solubility of permanganates is most likely to be similar to which of these groups?

A

chlorates

11
Q

Which of the following compounds is not soluble in water?

A

calcium carbonate

12
Q

A solution of silver nitrate (AgNO3 ) is added to a solution of sodium hydroxide (NaOH). In the precipitation reaction that occurs, which ions will be spectator ions?

A

Na+ and NO3−

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