Water of Crystallization

Q.

A compound X having 2 molecules of water of crystallization.On heating, it becomes a new compound Y used in plastering of fractured bones.The compound X is ___ .

Q.

What would you observe when crystals of copper (II) sulphate and iron (II) sulphate are separately heated in two test tubes ?

Q.

Give a chemical test to distinguish between the following pairs of compounds.

Iron II chloride and Iron III chloride solution

Q. What would you observe when a mixture of iron filings and sulphur powder is heated strongly?

1. No change at all.
   
2. The mixture will change its state.
   
3. No change in the chemical composition of the mixture.
   
4. A new compound known as ferrous sulphide will be formed.
   

Q.

State the term :

A substance that contains water of crystallisation.

Q. Sublimation is the process of separating a liquid from its solution by evaporating it and then condensing its vapour.

1. True
2. False

Q. State whether the following statement is true or false:
Copper sulphate crystals are always wet due to the presence of water of crystallisation in them.

Q.

59. Define water of crystallization.

Q.

$CaS{O}_4.2H_{2}O\underrightarrow{\Delta {120}^{\circ }C}\underset{–}{A}+3H_{2}O.A$ is

1. 2CaSO₄ . H₂O

2. CaSO₄ .H₂O

3. CaSO₄ . 3H₂O

4. CaSO₄ . 2H₂O

Q.

Two metals $\mathrm{X}$ and $\mathrm{Y}$ form the salts ${\mathrm{XSO}}_4$ and ${\mathrm{Y}}_2{\mathrm{SO}}_4$, respectively. The solution of salt ${\mathrm{XSO}}_4$ is blue in colour whereas that of ${\mathrm{Y}}_2{\mathrm{SO}}_4$ is colourless. When barium chloride solution is added to ${\mathrm{XSO}}_4$ solution, a white precipitate $\mathrm{Z}$ is formed along with a salt which turns the solution green. When barium chloride solution is added to ${\mathrm{Y}}_2{\mathrm{SO}}_4$ solution, then the same white precipitate $\mathrm{Z}$ is formed along with a colorless common salt solution.
What could the metals $\mathrm{X}$ and $\mathrm{Y}$ be?

Q.

Hard water is suitable for refining sugar.

1. True
2. False

Q. Water of crystallisation is responsible for ......... of the crystals.

1. geometric shape and colour
2. geometric shape
3. colour
4. number of crystal

Q. Which of the following are efflorescent substances?

1. $Cu{SO}_4.5H_{2}O$
2. ${Na}_2{CO}_3.10H_{2}O$
3. ${\left({NH}_4\right)}_2{SO}_4$
4. $K_2{SO}_4.{Al}_2{\left({SO}_4\right)}_3.24H_{2}O$

Q.

Some salts while crystallizing out from their solution, unite with a definite quantity of water which is known as: ________

Q. The number of water of crystallization molecules present in one molecule of plaster of Paris is:

1. 4
2. 0.5
3. 0.2
4. 1

Q. What is meant by water of crystallisation of a substance? Describe an activity to show that. [4 marks]

Q. One formula unit of gypsum contains ______ water molecules in it.

1. three
2. five
3. four
4. two

Q. How many molecules of water are present in one formula unit of copper sulphate pentahydrate?

1. 7
2. 5
3. 2
4. 10

Q.

If the water of crystallisation in gypsum is X and Y in washing soda then the value of X + Y is ________

1. 8
2. 10
3. 12
4. 14

Q. A salt formed after the neutralisation reaction is a combination of of an acid and of a base.

1. volume
2. anion
3. mass
4. cation

Q.

Choose the salt that most appropriately fits the description given in the following

[AgCl, MgCl_2, NaHSO₄, PbCO₃ , ZnCO₃, , KCO_3, Ca(NO)₃]

On heating this salt gives a yellow residue when hot and white when cold

Q. Molecular formula of Glauber salt is:

1. $CuS{O}_4.5H_{2}O$
2. $N{a}_{2}S{O}_4.10H_{2}O$
3. $MgS{O}_4.7H_{2}O$
4. $FeS{O}_4.7H_{2}O$

Q.

Which of the following formulas are correct?

1. Gypsum - CaSO${}_4$.2H${}_2$O

2. White vitriol - ZnSO${}_4$.5H${}_2$O

3. Plaster of Paris - CaSO${}_4$.1/2 H${}_2$O

4. Blue vitriol - CuSO${}_4$.5H${}_2$O