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Class 10 Chemistry Chapter 18 Salts Test 2 – Full unit
Class 10 Chemistry Chapter 18 Salts Full Unit Test 2
Prepare for your matric Chemistry examination with the Class 10 Chemistry Chapter 18: Salts – Class Test 2 (Full Unit Test), part of the Punjab Board 2027 Model Papers and Chapter-Wise Test Series. Designed for students following the new Class 10 Chemistry syllabus issued by PECTAA Punjab, this full-unit test helps students revise important concepts, practise examination-style questions, and assess their understanding of the Salts chapter. Use this Class 10 Chemistry Chapter 18 test for effective revision, self-assessment, and board examination preparation. Visit 786Times.com for more Punjab Board 2027 Model Papers, chapter-wise Chemistry tests, and educational resources to support your matric examination preparation.
CHEMISTRYCHAPTER-18 (OBJECTIVE)CLASS TEST-2
1. When an acid reacts with a base, it form:(Q-1)
(a) Salt and hydrogen(b) Salt and oxygen(c) Salt and water(d) Acid and water
✔ Answer: (c) Salt and water
2. Each sodium ion is surrounded by chloride ions is:(Q-6)
(a) Four(b) Five(c) Six(d) Eight
✔ Answer: (c) Six (each Na+ is surrounded by 6 Cl−)
3. A large amount of energy is required to melt ionic compounds due to:(Q-9)
(a) covalent bonding(b) hydrogen bonding(c) electrostatic attraction between ions(d) metallic bonding
✔ Answer: (c) electrostatic attraction between ions
4. The factor affects the solubility of a salt is:(Q-14)
(a) Colour of salt(b) Nature of salt(c) Shape of crystal(d) Density only
✔ Answer: (b) Nature of salt
5. Sulfates of which metals are insoluble in water?(Q-18)
(a) Sodium and potassium(b) Barium and lead(c) Ammonium and calcium(d) Magnesium and zinc
✔ Answer: (b) Barium and lead (BaSO4, PbSO4)
6. Soluble salts are prepared mainly by using:(Q-20)
(a) One method(b) Two methods(c) Three methods(d) Four methods
✔ Answer: (b) Two methods
7. Copper sulphate is commonly used as:(Q-24)
(a) fertilizer(b) fungicide(c) fuel(d) disinfectant
✔ Answer: (b) fungicide (CuSO4)
8. Excess insoluble base or metal is removed by:(Q-26)
(a) Evaporation(b) Distillation(c) Filtration(d) Crystallization
✔ Answer: (c) Filtration
9. Which step is used to remove excess base or metal?(Q-28)
(a) Evaporation(b) Filtration(c) Crystallization(d) Cooling
✔ Answer: (b) Filtration
10. Which process is used to remove excess zinc metal?(Q-30)
(a) Evaporation(b) Cooling(c) Filtration(d) Crystallization
✔ Answer: (c) Filtration
786Times — Chemistry Chapter-18 (Objective)
CHEMISTRYCHAPTER-18 (SUBJECTIVE)CLASS TEST-2
Attempt any 10 Questions. 10 × 2 = 20
i. What is a salt?(Q-2)
Ans: A salt is an ionic compound formed when the hydrogen of an acid is replaced by a metal (or ammonium) ion. Example: NaCl.
ii. Write the arrangement of ions in sodium chloride (NaCl).(Q-5)
Ans: NaCl forms a giant cubic lattice. Each Na+ ion is surrounded by six Cl− ions, and each Cl− ion is surrounded by six Na+ ions (6 : 6 arrangement).
iii. Why was common salt valuable in the past?(Q-7)
Ans: It was scarce and hard to obtain, and it was the main food preserver (meat and fish) before refrigeration, so it was traded like money and even given as wages.
iv. Why do ionic compounds have high melting points?(Q-8)
Ans: Oppositely charged ions in the giant lattice are held by very strong electrostatic forces of attraction. A large amount of energy is needed to break them.
v. How do ionic charge and ion size affect melting point?(Q-11)
Ans: Higher ionic charge and smaller ion size give stronger attraction between ions, so the melting point is higher. Example: MgO (Mg2+, O2−) melts higher than NaCl (Na+, Cl−).
vi. Why do ionic compounds not conduct electricity in solid state?(Q-12)
Ans: In the solid state the ions are fixed in the lattice and cannot move, so there are no free charge carriers.
vii. What is meant by a strong electrolyte? Give example.(Q-14)
Ans: A substance that ionizes completely in water (or when molten) and conducts electricity well. Examples: NaCl, HCl, NaOH.
viii. Which salts are always soluble in water?(Q-16)
Ans: All sodium, potassium and ammonium salts, and all nitrates.
ix. Write the names of two insoluble chlorides and sulphates.(Q-18)
Ans: Insoluble chlorides: silver chloride (AgCl), lead chloride (PbCl2).
Insoluble sulphates: barium sulphate (BaSO4), lead sulphate (PbSO4).
Insoluble sulphates: barium sulphate (BaSO4), lead sulphate (PbSO4).
x. Name the two methods used for the preparation of soluble salts.(Q-20)
Ans: (1) Acid + excess insoluble base / metal / carbonate, then filtration.
(2) Acid + soluble alkali (titration method).
(2) Acid + soluble alkali (titration method).
xi. How soluble KNO3 can prepare?(Q-22)
Ans: By titration of KOH (alkali) with HNO3 using an indicator, then evaporating and crystallizing the solution.
KOH + HNO3 → KNO3 + H2O
KOH + HNO3 → KNO3 + H2O
xii. Why is the solution cooled slowly during crystallization?(Q-25)
Ans: Slow cooling gives large, well-shaped crystals; fast cooling gives small, impure crystals.
xiii. Why are crystals washed with cold distilled water?(Q-27)
Ans: To remove soluble impurities from the surface. Cold water is used so the crystals do not dissolve.
xiv. Why is constant stirring done during the reaction?(Q-29)
Ans: To mix the reactants well, speed up the reaction and make sure all the acid reacts evenly.
786Times — Chemistry Chapter-18 (Subjective)
