SSLC Chemistry Passing Package 2026 | Important Questions & Answers

Chapter 1: Chemical Reactions and Equations

1. Among the following reactions, which resembles the reaction in which a reddish-brown coat forms on the surface of iron articles?

A. Coating of chromium on iron articles

B. Formation of silver sulphide on silver articles by oxidation

C. Obtaining copper coat on iron nail by electrolysis

D. Formation of grey colour silver by decomposition of silver chloride

Answer: Option C

2. Suggest any two methods to prevent rancidity.

Answer:

1. Flush the food with nitrogen gas.

2. Store food in airtight containers.

3. When sodium sulphate solution is added to Barium Chloride solution, a white precipitate will be formed. Which are the ions responsible for this precipitate formation?

   Answer:Barium sulphate precipitate is formed.

   Ba2++SO42−→BaSO4Ba^{2+} + SO_4^{2-} → BaSO_4Ba2++SO42−​→BaSO4​

   
   

4. List the observations that indicate a chemical reaction has taken place.

   Answer:

   • Change in state

   • Temperature change

   • Evolution of gas

   • Change in colour

     
     

5. Draw the apparatus used in electrolysis of water and label:

   • Graphite rod

   • Oxygen

6. Analyse the experiment and identify the molecular formula of solution Y that gives yellow precipitate with KI.

   A. Pb(NO₃)₂ and KNO₃

   B. PbI₂ and KNO₃

   C. Pb(NO₃)₂ and KI

   D.Pb(NO₃)₂ and K₂SO₄

   Answer: Option C

7. Balance the following equations

   1. Magnesium oxide + Hydrochloric acid

MgO+2HCl→MgCl2+H2OMgO + 2HCl → MgCl_2 + H_2OMgO+2HCl→MgCl2​+H2​O

2. Calcium hydroxide + Carbon dioxide

Ca(OH)2+CO2→CaCO3+H2OCa(OH)_2 + CO_2 → CaCO_3 + H_2OCa(OH)2​+CO2​→CaCO3​+H2​O

3. Zinc carbonate

ZnCO3→ZnO+CO2ZnCO_3 → ZnO + CO_2ZnCO3​→ZnO+CO2​

4. Formation of ammonia

N2+3H2→2NH3N_2 + 3H_2 → 2NH_3N2​+3H2​→2NH3​

5. Sodium oxide + Water

Na2O+H2O→2NaOHNa_2O + H_2O → 2NaOHNa2​O+H2​O→2NaOH

6. Potassium + Water

2K+2H2O→2KOH+H22K + 2H_2O → 2KOH + H_22K+2H2​O→2KOH+H2​

8. Silver chloride turns grey when exposed to sunlight because it:

   A. Decomposes to form silver

   B. Decomposes to form chlorine

   C. Combines with oxygen

   D. Reacts with atmospheric moisture

   Answer: Decomposes to form silver.

9. Balance the following

   3Mg+N2→Mg3N23Mg + N_2 → Mg_3N_23Mg+N2​→Mg3​N2​2NaOH+H2SO4→Na2SO4+2H2O2NaOH + H_2SO_4 → Na_2SO_4 + 2H_2O2NaOH+H2​SO4​→Na2​SO4​+2H2​O2Al(OH)3→Al2O3+3H2O2Al(OH)_3 → Al_2O_3 + 3H_2O2Al(OH)3​→Al2​O3​+3H2​O

10. Zinc oxide is reduced by coke

    ZnO+C→Zn+COZnO + C → Zn + COZnO+C→Zn+CO

11. Magnesium ribbon burns with a dazzling white flame. What type of reaction?

    Answer: Combination Reaction

    
    

12. Why must chemical equations be balanced?

    Answer:To obey the Law of Conservation of Mass.

    
    

13. Measures to prevent rusting of iron

    • Painting

    • Greasing

    • Alloying

    • Galvanization

    • Chrome plating

    
    

14. What is rancidity?

    Answer:Oxidation of oils and fats causing bad smell and taste in food.

    
    

15. Balance the following

1. calcium carbonate   -------- calcium oxide +  carbon dioxide

   1. Ans: CaCO3 ------ CaO + CO2

2. hydrogen + chlorine------- hydrogen  chloride

   1. Ans :repeated

3. magnesium + hydrochloric acid  -------- magnesium chloride + hydrogen 

   1. Ans:Mg + 2 Hcl----- Mgcl2 + H2

4. N2 + H2------ NH3

   1. Ans: N2 + 3 H2------ 2NH3

5. NaOH + H2SO4 -------- Na2SO4 +  H2O

   1. Ans : 2 NaOH + H2 SO4 ----- Na2 SO4 + 2 H2 O

6. Mg + O2 ------ MgO

   1. Ans : 2 Mg  + O2 ------2 MgO

7. copper reacts with concentric nitric acid

   1. Ans:  2Cu +  2HNO3-----2 Cu( NO3)2 +H2

8. Silver Nitrate solution is added to potassium Bromide solution

   1. Ans:AgNO3 + KBr------KNO3+ AgBr

9. hydrogen reacts with chlorine to form hydrogen chloride

   1. Ans: H2 + Cl2 ----- 2 HCl

10. AgCl ------- Ag + Cl2

    1. Ans:2 AgCl ------ 2 Ag + Cl2

11. Fe + H2O ------ Fe3O4  + H2

    1. Ans:3 Fe  + 4 H2 O ------ Fe3 O4 + 4 H2

12. N2 + H2 ----- NH3

    1. Ans: N2 + 3 H2 ----- 2 NH3 balanced

16. What are redox reactions?

    Answer:Reactions involving both oxidation and reduction.

17. Identify oxidized and reduced substance

CuO+H2→Cu+H2OCuO + H_2 → Cu + H_2OCuO+H2​→Cu+H2​O

• Oxidized: H₂ → H₂O

• Reduced: CuO → Cu

18. Difference between Endothermic and Exothermic reaction

Endothermic	Exothermic
Heat is absorbed	Heat is released

Chapter 2: Acids, Bases and Salts

1. If the pH of a solution is 7, the pH can be increased by adding

A. Acid

B. Salt

C. Sodium hydroxide

D. Carbon dioxide

Answer: Sodium hydroxide

2. Acid in nettle leaves

   Answer: Methanoic acid

   
   

3. Nature of salt formed

   

   Beaker A → Alkaline saltBeaker B → Acidic salt

   
   

4. Molecular formula and use of salts

Salt	Formula
Bleaching powder	CaOCl₂
Plaster of Paris	CaSO₄ · ½H₂O
Sodium carbonate	Na₂CO₃

5. What is a strong acid?

   An acid having high concentration of H⁺ ions.

   
   

6. Tooth decay

   When mouth pH falls below 5.5, tooth enamel dissolves.

   Prevention: Use basic toothpaste.

   
   

7. Acid vs Base

Acid	Base
Sour taste	Bitter taste
Corrosive	Soapy touch

8. Chloro-alkali process products

   • Sodium Hydroxide

   • Hydrogen gas

   • Chlorine gas

     
     

9. What is acid rain?

   Rainwater with pH less than 5.6.

   
   

10. Gas released when acid reacts with carbonate

    Carbon dioxide

    
    

11. Formula of baking soda

    NaHCO₃

    
    

12. Neutralization reaction

    Reaction between acid + base → salt + water

    
    

13. Acids present in substances

Substance	Acid
Curd	Lactic acid
Gastric juice	Hydrochloric acid

Chapter 3: Metals and Non-Metals

1. Exothermic vs Endothermic reactions

   • Calcium oxide reaction → Exothermic

   • Heating ferrous sulphate → Endothermic

     
     

2. Copper heating reaction

   2Cu+O2→2CuO2Cu + O_2 → 2CuO2Cu+O2​→2CuO

   Hydrogen reduces CuO.

   
   

3. Aluminium + Steam

   Product: Aluminium oxide

   
   

4. Thermite reaction

   Fe2O3+2Al→2Fe+Al2O3+HeatFe_2O_3 + 2Al → 2Fe + Al_2O_3 + HeatFe2​O3​+2Al→2Fe+Al2​O3​+Heat

   Use: Welding railway tracks.

   
   

5. Brass composition

   Copper + Zinc

   
   

6. Metals found in native state

   • Gold

   • Silver

     
     

7. Amphoteric oxide

   Oxides reacting with both acid and base.

   Example: Aluminium oxide

Chapter 4: Carbon and Its Compounds

1. Property responsible for large molecules

   Catenation

   
   

2. Simplest hydrocarbon

   MethaneFormula: CH₄

   
   

3. Esterification

   Reaction between acid + alcohol → ester + water

   CH3- CH2OH --------- CH2=CH2 + H2O ( in the presence of concentrated sulphuric acid)

   
   

4. Cleaning action of soap

   Soap molecules form micelles that trap dirt and grease.

   Soaps are sodium or potassium salt of long chain carboxylic acid

   Soap molecules form missiles in which the ionic and interacts with water and faces outside

   Carbon chain of the soap interacts with oil or dirt

   This forms emulsion in water the soap molecules pull out the dirt and watch the clothes clean 

   
   

5. Functional group in Pentanal

   –CHO (Aldehyde)

   
   

6. Difference between saturated and unsaturated hydrocarbons

Saturated	Unsaturated
Single bond	Double / Triple bond
Blue flame	Sooty flame

7. Hydrogenation

C2H4+H2→C2H6C_2H_4 + H_2 → C_2H_6C2​H4​+H2​→C2​H6​

Catalyst: Nickel / Palladium

8. What is catenation?

Ability of carbon atoms to bond with other carbon atoms forming chains.

9. Write the structure of formula of an unsaturated carbon compound containing four carbon atom and a Ketone functional group

10. Write the structure of a n butane and ISO butane

11. Write the dot structure of Nitrogen Propynen molecule and methane

12. The first member of a group of carbon compound is CH3 Cl write the molecular formula and the name of the third member of this group

C3 H7 Cl-- chloro propane

13. Carbon atom do not form C4 + cat ion and C4 - and Ion why

    Carbon can gain for electron but it would be difficult for the nucleus with 6 Proton to hold on to 10 electron that is 4 extra electron. It can lose for electron but it would require large amount of energy to remove four electrons leaving behind a carbon cat Ion with 6 Proton in its nucleus holding just two electron

14. How many single and double bond in CH3COOH

    Single bond -5 and Double bond -1

15. Write  the structure formula of cyclopentane propanol butyne

16. Name the substance that do not undergo chemical change that is used in the reaction of converting a compound containing a carbon carbon double bond into a compound containing only single bond write an example for this reaction in the form of equation

    This is called catalyst, Nickel and Palladium are the best example ,CH2= CH2--------- C2H6

17. Another structure with the same molecular formula of the compound in the following structural formula

Ans: D

18. Molecular and structure formula of propanoic  acid

19. Write the structure of formula of the compound obtained when one atom of Hydrogen in Ethane replaced by CHO group