Practice Worksheet for Exam 2024 CBSE Boards All Chemistry

 

1.  Sodium and chlorine are reacted, and as a result, sodium chloride is formed, which is also called table salt. What option gives the reactants and products of the reaction?

(a) Reactants – sodium; products – chlorine

(b) Reactants – sodium and table salt; products – chlorine

(c) Reactants – tables salt; products – sodium and chlorine

(d) Reactants – sodium and chlorine; products – sodium chloride

2. Which of the following reaction can also be termed a thermal decomposition reaction?

(a) Combination reaction              (b) Decomposition reaction

(c) Displacement reaction             (d) Double displacement reaction

3. The image shows some chemical reactions.

Which option identifies the reactants and products of the reactions?

Q4) A student performs an experiment to form aluminium chloride from aluminium and chlorine. Which of the following option gives the chemical equation of the reaction?

(a) Al + Cl₂ → AlCl₂                 (b) 2Al + Cl₂ → 2AlCl

(c) 2Al + 3Cl₂ → 2AlCl₃           (d) 3Al + 3Cl₂ → 3AlCl₃

Q5. Give the ratio in which hydrogen and oxygen are present in water by volume.

(a) 1:2        (b) 1:1                 (c) 2:1                (d) 1:8

Q6) A researcher adds barium hydroxide to hydrochloric acid to form a white-coloured barium chloride. Which of the following option gives the balanced chemical equation of the reaction?

(a) HCl + Ba(OH)₂ → BaCl₂ + 2HOH

(b) 2HCl + Ba(OH)₂ → BaCl₂ + 2HOH

(c) 2HCl + Ba(OH)₂ → BaH₂ + 2HCl + O₂

(d) HCl + 2Ba(OH) → 2BaCl₂ + 2HOH + O₂

Q7. One of the following processes does not involve a chemical reaction, that is:

(a) Melting of candle wax when heated

(b) Burning of candle wax when heated

(c) Digestion of food in your stomach

(d) Ripening of banana

Q8) A student wrote a chemical equation of the reaction between carbon monoxide and hydrogen as,

CO2 + 2H₂ → CH₃OH.

How can the reaction be classified?

(a) The reaction is an example of a combination reaction as a compound separates into two compounds.

(b) The reaction is an example of a decomposition reaction as a compound dissociates into two compounds.

(c) The reaction is an example of a combination reaction as two compounds react to form a single compound.

(d) The reaction is an example of a decomposition reaction as two compounds react to form a single compound.

Q9) The chemical formula of magnesium oxide is ______.

(a) MgO₂            (b) Mg₂O              (c) MgO       (d) Mg(OH)₂

Q10) A student learns that some products are formed as a result of combining two compounds while some compounds are formed as a result of the dissociation of two compounds. The image shows two reactions.

Which reaction is an example of a combination reaction and a decomposition reaction?

(a) Both reactions are examples of combination reaction

(b) Both reactions are examples of a decomposition reaction

(c) Reaction P is an example of a combination reaction, while reaction Q is an example of a decomposition reaction

(d) Reaction P is an example of a decomposition reaction, while reaction Q is an example of a combination reaction

Q11) From the following, which one is an example of a chemical reaction?

(a) Grapes get fermented                                        (b) Breakdown of food

(c) Formation of curd                                                  (d) All of the above

Q12) A student adds lead and silver to two different test tubes containing an equal amount of copper sulphate solution. The student observes that the colour of the solution in the test tube with lead changes. What explains the change in the colour of the solution?

(a) A displacement reaction takes place as lead replaces copper from the solution.

(b) A combination reaction takes place as lead combines with sulphate in the solution.

(c) A decomposition reaction takes place as copper dissociates from sulphate in the solution.

(d) A double displacement reaction takes place as copper dissociates from sulphate and lead combines with sulphate in the solution.

Q13) Which of the following reactions is used in black-and-white photography?

(a) Combination Reaction                 (b) Decomposition Reaction

(c) Displacement reaction                 (d) Oxidation reaction

Q14) What happens when lead nitrate reacts with potassium iodide?

(a) They will not react

(b) A large amount of hydrogen will be released

(c) Yellow ppt of lead iodide and potassium nitrate will be produced

(d) Evolution of gas will occur

Q15) The chemical reaction between potassium chloride and silver nitrate is given by the chemical equation,

AgNO₃ + KCl → AgCl + KNO_3.

What can be inferred from the chemical equation?

(a) Silver nitrate and potassium undergo a decomposition reaction to form silver chloride and potassium nitrate

(b) Silver nitrate and potassium undergo a displacement reaction to form silver chloride and potassium nitrate

(c) Silver nitrate and potassium undergo a combination reaction to form silver chloride and potassium nitrate

(d) Silver nitrate and potassium undergo a double displacement reaction to form silver chloride and potassium nitrate

Q16) Which of the following shows an oxidation reaction?

(a) Gain of oxygen                      (b) Loss of oxygen

(c) Gain of hydrogen                  (d) None of the above

Q17) The image shows a reaction between zinc and hydrogen.

Which option shows oxidation?

(a) Zn → Zn⁺²     (b) 2H⁺ → H₂     (c) Zn⁺² → Zn      (d) H₂ → 2H⁺

Acid Base and Salts

Q1 Which Acid is present in Tomato?

(A) Citric Acid     (B) Oxalic Acid      (C) Lactic Acid      (D) HCl

Q2. Which of the following is a strong acid?

(A) HCl pH 1      (B) CH₃COOH pH 5    (C) Lemon juice pH 2.2   (D) Pure Milk pH 6

Q3. Na₂CO₃.10H₂O is known as –

(A) Baking soda   (B) Baking powder  

(C) Washing soda   (D) Bleaching powder

Q4. pH value less than 7 indicates that the solution is –

(A) Acidic    (B) Basic     (C) Neutral     (D) No effect

Q5. Which of the following is neutral salt?

(A) NH₄Cl    (B) CH₃COONH₄   (C) CH₃COONa     (D)Na₂CO₃

Q6. Lactic Acid is present in –

(A) Orange    (B) Tea    (C) Curd     (D) Vinegar

Q7. Farmers neutralise the effect of Acidity on the soil by adding –

(A) Slaked lime    (B) Gypsum    (C) Caustic soda    (D) Baking soda

Q8. Which of the following are present in a dilute Aqueous solution of hydrochloric acid?

(A) H₃O + Cl^–     (B) H₃O + OH^–    (C) Cl^– + OH^–     (D) Unionised HCl

Q9. CuSO₄.5H₂O: In this Compound, the water molecule is called –

(A) Pure water           (B) Water of crystallisation

(C) Soda water         (D) None of these

Q10. Which of the following salts does not contain water of crystallisation?

(A) Blue vitriol    (B) Baking soda     (C) Washing soda     (D) Gypsum

Q11. An aqueous solution turns the red litmus solution blue. Excess addition of which of the following solutions would reverse the change?

(A) Baking powder                                 (B) Lime  

(C) Ammonium hydroxide solution    (D) Hydrochloric acid

Q12. In which pH range does our body work to survive in the atmosphere?

(A) 5.5 to 8.5   (B) 7.0 to 7.8    (C) 2.3 to 7.0    (D) 7.5 to 12.5

Q13. What is the chemical formula of POP (Plaster of Paris)?

(A) CaSO₄.2H₂O   (B) CaSO₄.3H₂O   (C) CaSO₄.1/2H₂O   (D) CaCO₃.1/2H₂

Q14. What happens when a solution of an acid is mixed with a solution of a base in a test tube?

(i) The temperature of the solution increases

(ii) The temperature of the solution decreases

(iii) The temperature of the solution remains the same

(iv) Salt formation takes place

(A) (i) only   (B) (i) and (iii)     (C) (ii) and (iii)    (D) (i) and (iv)

Q15. Which salt is acidic in nature?

(A) NH₄Cl    (B) CH₃COONH₄   (C) NaCl    (D)Na₂CO₃

Q16. When a base reacts with a metal, it forms a salt, and hydrogen gas is released. By what method can the presence of hydrogen be detected?

(A) by water                             (B) by litmus paper 

(C) by methyl orange             (D) by a burning candle

Q17. The image shows the pH values of four solutions on a pH scale.

Which solutions are alkaline in nature?

(A) A and B   (B) B and C    (C) C and D   (D) A and D

Q18. At what temperature is gypsum heated to form Plaster of Paris?

(A) 35°C     (B) 70°C    (C) 80°C    (D) 100°C

Q19. Sodium carbonate reacts with hydrochloric acid and produces –

(A) NaCl   (B) CO₂   (C) H₂O   (D) All of the above

Q20. Which acid is present in tamarind?

(A) Tartaric acid   (B) Oxalic Acid    (C) Lactic Acid    (D) Citric Acid

Metal and Non metals

Q1) Which of the following oxides of iron would be obtained on the prolonged reaction of iron with steam?

a) FeO           b) Fe₂O₃             c) Fe₃O₄            d) Fe₂O₃ and Fe₃O₄

Q2) A non-metal used to preserve food material is:

a) Carbon       b) Phosphorus       c) Sulphur     d) Nitrogen

Q3) The arrangement for Copper, Tin, Lead and Mercury, according to the reactivity series, is:

a) Tin> Lead> Copper> Mercury          b) Lead> Copper> Mercury> Tin

c) Copper> Mercury> Tin> Lead         d) Mercury> Tin> Lead> Copper

Q4) The metals that float when treated with water are:

a) Manganese and sodium        b) Sodium and calcium

c) Magnesium and sodium        d) Magnesium and calcium

Q5) Aluminium is used for making cooking utensils. Which of the following properties of aluminium are responsible for the same?

(i) Good thermal conductivity      (ii) Good electrical conductivity

(iii) Ductility                                      (iv) High melting point

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

Q6) When hydrochloric acid is added to barium hydroxide, a white-coloured compound is formed. Which of the following option gives the complete chemical reaction?

a) HCl + Ba(OH)₂ → BaCl₂ + 2HOH

b) 2HCl + Ba(OH)₂ → BaCl₂ + 2HOH

c) 2HCl + Ba(OH)₂ → BaH₂ + 2HCl + O₂

d) HCl + 2Ba(OH) → 2BaCl₂ + 2HOH + O₂

Q7) What happens when a pellet of sodium is dropped in water?

(a) It catches fire and forms oxide

(b) It absorbs heat and forms oxide

(c) It catches fire and forms hydroxide

(d) It absorbs heat and forms hydroxide

Q8) The chemical reaction between a piece of copper and nitric acid is given by the chemical equations,

Cu + HNO₃ → Cu(NO₃)₂ + H₂

H₂ + HNO₃ → H₂O + NO₂

What can be inferred from the chemical equation?

a) Copper causes the oxidation of HNO₃ to form NO₂

b) Hydrogen gas gets oxidised by HNO₃ to form water

c) Gas reacts with oxygen in the air to form water

d) Nitrate reacts with hydrogen to form NO₂ and H₂O

Q9) Which of the following options gives the process of extraction of mercury from its ore cinnabar?

(a) Cooling cinnabar in the presence of excess air

(b) Cooling cinnabar to convert it into mercuric oxide and then heating it

(c) Cinnabar to convert it into mercuric oxide and then heating it again

(d) Cinnabar in the presence of limited air, and then adding a small amount of water

Q10) The image shows the electrolytic refining of copper.

Which of the following options explains the process of obtaining pure copper?

(a) When current is passed, pure copper from the anode deposits to the cathode.

(b) When current is passed, pure copper from the anode deposits in the electrolytic solution.

(c) When current is passed, pure copper from the electrolytic solution deposits at the anode.

(d) When current is passed, pure copper from the electrolytic solution deposits at the cathode.

Q11) When calcium oxide is added to water, it completely dissolves in water without forming bubbles. What products are formed in this reaction?

(a) Ca and H₂        (b) Ca and H₂O₂      (c) Ca(OH)₂         (d) CaH₂

Q12) A student studying the chemical properties of metals finds incomplete chemical reactions in his book, as shown below:

MgO + HNO₃ →

Which option completes the reaction?

(a) MgO + HNO₃ → Mg₃N₂ + 4H₂O

(b) MgO + HNO₃ → Mg + NO₂ + O₂

(c) MgO + HNO₃ → Mg(OH)₂ + 2NO₂

(d) MgO + HNO₃ → Mg(NO₃)₂ + H₂

Q13) Which of the following can undergo a chemical reaction?

a) MgSO₄ + Fe                                      b) ZnSO₄ + Fe

c) MgSO₄ + Pb                                      d) CuSO₄ + Fe

Q14) Pick the statement which is correct about the non-metal.

a) Br is an example of a liquid non-metal.

b) Graphite is a good conductor of electricity

c) Most of the non-metal oxides are acidic

d) All of these

Q15) A student wrote two incomplete chemical reactions:

Which option completes the reactions to form a balanced chemical equation?

(a) X – P₅O₄(s); Y – (MgO)₂(s)           (b) X – 4PO₁₀(s); Y – 4MgO(s)

(c) X – P₄O₁₀(s); Y – 2MgO(s)            (d) X – 5P₄O₂(s); Y – Mg₂O₂(s)

Q16) When a non-metal is allowed to react with water:

a) CO₂ gas is formed                                                    b) H2 gas is formed

c) Product formed depends on the temp.             d) No products are formed

Q17) Aqua regia is a freshly prepared mixture of concentrated HNO3 and concentrated HCl in the ratio of:

a) 1:3, respectively                      b) 2:3, respectively

c) 3:1, respectively                      d) 3:2, respectively

 

Carbon and Its compounds

Q1) The electronic configuration of an element is found to be 2, 4. How many bonds can one carbon atom form in a compound?

(a) 1     (b) 2      (c) 4    (d) 6

Q2) The following chemical reaction shows the addition of chlorine to methane in the presence of sunlight:

CH₄ + Cl₄ → X

What is likely to be the product of the reaction represented by “X”?

(a) CH₄+ H₂SO₄    (b) CH₃Cl + HCl    (c) CHCl₃ + HCl     (d) CH₃Cl + H₂SO₄

Q3) The image represents the structure of a few hydrocarbon compounds.

Which of these compounds can be classified as alkynes?

(a) Only (A)     (b) Only (B)     (c) Both (A) and (D)  (d) Both (B) and (C)

Q4) The below image represents a chemical reaction where ethanol is oxidised using potassium dichromate and sulphuric acid.

Which of the following option represents the product “X”?

(a) CH₂O           (b) CH₃CH            (c) CH₃H₂O          (d) CH₃COOH

Q5) The given image represents the structure of a carbon compound known as ethane.

Which of the following option explains the naming of ethane?

(a) The presence of a functional group connected with a single bond

(b) As it contains two carbon atoms, and a single bond connects the carbon atoms

(c) Carbon compound with a total number of eight atoms is named ethane

(d) As it contains six hydrogen atoms, and a single bond connects the carbon and hydrogen atom

Q6) The following image represents a carbon compound.

Which functional group is present in the compound?

(a) Alcohol     (b) Aldehyde        (c) Carboxylic acid    (d) Ketone

Q7) A carbon compound contains two atoms of carbon. Which name should the carbon compound bear?

(a) Butane      (b) Ethane        (c) Methane     (d) Propane

Q8) The following chemical reaction shows the addition of chlorine gas to hydrocarbon in the presence of sunlight.

CHCl₃ + Cl₂ → CCl₄ + HCl

How does chlorine react to a hydrocarbon compound in the presence of sunlight?

(a) It adds hydrogen to the compound

(b) It adds an oxygen atom to the compound

(c) It substitutes hydrogen atom from the compound

(d) It breaks double and triple bonds into a single bond

Q9) Which of these functional groups can combine with carbon to produce alcohol?

Q10) A student studies that vinegar, which is a diluted form of ethanoic acid, freezes during winter. What does this suggest about the physical properties of pure ethanoic acid?

(a) It has a low boiling point                (b) It has a low melting point

(c) It has a very high boiling point      (d) It has a very high melting point

Q11) Which of the following is the molecular formula of cyclobutane?

a) C₄H₁₀           b) C₄H₆              c) C₄H₈                    d) C₄H₄

Q12) A student studies that a soap molecule has two ends, one of which is an ionic end, and the other is the carbonic chain. Which option explains the interaction of a soap molecule with oil?

(a) Ionic end of the soap interacts with the oil

(b) The closest end of the soap interacts with the oil

(c) Carbonic chain end of the soap interacts with the oil

(d) Ends of the soap randomly interact with the oil

Q13) Methane, ethane and propane are said to form a homologous series because all are:

(a) Hydrocarbons                               (b) Saturated compounds

(c) Aliphatic compounds                  (d) Differ from each other by a CH₂ group

Q14) Which of the following belongs to a homologous series of alkynes?

(a) C₆H₆          (b) C₂H₆           (c) C₂H₄             (d) C₃H₄

Q15) A student studies that soap solution results in micelle formation, which helps to remove dirt. It has a unique orientation which helps in keeping the dirt out of the water, as shown in the image.

What helps the dirt to rise away?

(a) Suspension of the dirt in the micelles

(b) A collection of water molecules in the centre of the micelle

(c) The attraction between the ionic end and the dirt to remove it

(d) Mixing of the soap molecules along with the dirt to make it heavier

Q16) Choose the correct statement.

(a) The ethene molecule is made up of 2 carbon atoms and 4 hydrogen atoms

(b) Each carbon atom shares three electrons with three hydrogen atoms to form three carbon-hydrogen single covalent bonds

(c) In ethane, the two carbon atoms share one pair of electrons among themselves to form one carbon-carbon single covalent bond

(d) All of the above

Q17) Which of the following is the property of ionic compounds?

(a) They have high melting and boiling points

(b) They conduct electricity in solution or in a molten state

(c) Both (a) and (b)

(d) None of the above

Q18) Which of the following is not a characteristic of fullerenes?

(a) Of all the fullerene, the C60 allotrope is the most stable

(b) Its shape is similar to that of a soccer ball

(c) It contains only fused six-membered carbon-carbon rings

(d) Its hardness is lower than that of a diamond

Q19) How many single bonds are present in methane?

(a) Four              (b) Five         (c) Six          (d) Three

Q20) A hydrocarbon should have a minimum of ______ carbon atoms to show isomerism.

(a) Three            (b) Four             (c) Fived              (d) Six