Precipitation Reaction

Q.

Barium chloride reacts with aluminium sulfate to give aluminium chloride and a precipitate of barium sulfate.

Translate and balance

Q.

When sodium sulphate solution is added to barium chloride, a white precipitate is formed. Write the chemical name of precipitate obtained and type of chemical reaction involved in this process.

Q.

Write the chemical reaction where the following changes are observed.

(a) Gas is evolved

(b) Colour change is noticed

(c) Precipitate is formed

(d) Physical state is changed

Q.

Give an example of each of the following chemical changes.

(a) A reaction involving.

(i) Change of state.

(ii) Formation of the precipitate.

(b) An exothermic and an endothermic reaction involving carbon as one of the reactants.

(c) A reaction where the colour change is noticed.

Q. Lead nitrate reacts with potassium iodide to form a yellow precipitate of .

1. ${\text{PbI}}_2$
2. ${\text{KNO}}_3$
3. ${\text{PbIO}}_3$

Q.

What is the colour of sodium sulphate formed due to the reaction of zinc sulphate with sodium hydroxide?

1. Pink

2. Colourless

3. Green

4. Blue

Q. The blue precipitate formed when aqueous copper sulphate reacts with aqueous ammonium hydroxide is.

1. copper hydroxide
2. ammonium sulphate
3. cupric oxide

Q. Question 15

What do you mean by a precipitation reaction? Explain by giving examples.

Q.

What do you observe when

(a) Lead nitrate is heated.

(b) Chlorine water is exposed to sunlight.

(c) Hydrogen peroxide is exposed to sunlight.

(d) $H_{2}S$ gas is passed through copper sulphate solution.

(e) Barium chloride is added to sodium sulphate solution.

Q.

Define the following terms:

(a) Chemical bond

(b) Effervescence

(c) Precipitate

Q. What is observed when ferrous sulphate reacts with sodium hydroxide solution?

1. Insoluble green precipitate
2. Gelatinous white precipitate
3. Soluble green precipitate
4. Insoluble pale blue precipitate

Q. What happens in the conical flask when two solutions - barium chloride and sodium sulphate are mixed together?

Q. Question 5

Three beakers labelled as A, B and C each containing 25 mL of water were taken. A small amount of $\text{NaOH}$, anhydrous ${\text{CuSO}}_4$ and $\text{NaCl}$ were added to the beakers A, B and C respectively. It was observed that there was an increase in the temperature of the solutions contained in beakers A and B, whereas, in case of beaker C, the temperature of the solution falls. Which one of the following statement(s) is/are correct?

(i) In beakers A and B, an exothermic process has occurred.
(ii) In beakers A and B, an endothermic process has occurred.
(iii) In beaker C exothermic process has occurred.
(iv) In beaker C endothermic process has occurred.

(a) (i) only
(b) (ii) only
(c) (i) and (iv)
(d) (ii) and (iii)

Q.

How does ammonium hydroxide react to distinguish ${\mathrm{FeCl}}_2$ solution from ${\mathrm{FeCl}}_3$ solution?

Q.

When a solution of sodium sulphate is added to a solution of barium chloride, a white precipitate appears. The white precipitate is due to formation of:

1. Sodium chloride

2. Barium chloride

3. Barium sulphate

4. Barium sulphide

Q. Write the name , colour and solubility of precipitate in excess of NaOH formed when-
1- Zinc Sulphate and
2- Ferric Chloride reacts sodium hydroxide

Q.

When a colourless compound X reacts with caustic soda, white precipitate of metal hydroxide is formed along with sodium nitrate. The precipitate formed is:

1. Calcium hydroxide

2. Ferrous hydroxide

3. Ferric hydroxide

4. Copper (II) hydroxide

Q.

The following equation represents double displacement reaction, what is the precipitate in this reaction?

$AgN{O}_3\left(aq\right)+NaI\left(aq\right)\to AgI\left(s\right)+NaN{O}_3\left(aq\right)$

1. Silver nitrate

2. Sodium iodide

3. Silver iodide

4. Sodium nitride

Q.

What do you observe when

(a) Lead nitrate is heated.

(b) Chlorine water is exposed to sunlight.

(c) Hydrogen peroxide is exposed to sunlight.

(d) $H_{2}S$ gas is passed through copper sulphate solution.

(e) Barium chloride is added to sodium sulphate solution.

Q.

What is the type of reaction between sodium sulphate and barium chloride?

1. Direction combination

2. Single displacement

3. Double displacement

4. Decomposition

Q.

Explain with the help of a chemical equation why lime water turns milky on passing carbon dioxide gas through it.

Q.

Name a gas which turns Nesslers reagent brown.

Q.

How will you distinguish between Ammonium hydroxide and Sodium hydroxide solution using Copper sulphate solution?

Q.

What happen when we heat

1. Copper sulphate

2. Ammonium dichromate

Q. Write the chemical reaction where the following changes are observed.

(a) Gas is evolved

(b) Colour change is noticed

(c) Precipitate is formed

(d) Physical state is changed

[4 marks]

Q. Compound A on strong heating in a boiling tube gives off reddish brown fumes and a yellow residue. When the aqueous solution of A is treated with a few drops of sodium hydroxide solution, a white precipitate appeared. Identify the cation and anion present in the compound A.

1. Copper (II) and nitrate
2. Lead (II) and chloride
3. Zinc and sulphate
4. Lead (II) and nitrate

Q.

Complete the reaction and then balance.

Barium chloride+ Sodium sulphate $\to$……….. +………………….

Q. Question 10
Explain the formation of scum when hard water is treated with soap.

Q.

Passage of Ammonia gas through copper sulphate solution forms pale blue precipitate of ___ .

Q.

${\mathrm{BaCl}}_2\left(\mathrm{aq}\right)+{\mathrm{Na}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)\to {\mathrm{BaSO}}_4\left(\mathrm{ppt}\right)+2\mathrm{NaCl}\left(\mathrm{aq}\right)$What is the colour of precipitate formed?

1. White

2. Black

3. Yellow

4. Blue