8881 + Interview Questions in Chemistry in Class 10 Page 151 InterviewSolution

7501.	Assertion (A) : Hexagonal arrays are placed in layers one above the other in the sctructure of graphite. Reason (R) : Fullerenes form another class of carbon allotropes.
Answer» Both (A) and (R) are true and (R) is CORRECT EXPLANATION of the assertion. Both (A) and (R) are true but (R) is not the correct explanation of the assertion. (A) is true but (R) is false. (A) is false but (R) is true. SOLUTION :Both assertion and reason statements are true but reason is not the correct explanation of assertion.

Discussion

7502.	Assertion (A) : Heaematite ore was purified by Hydraulic method. Reason (R ) : Haematite is oxide ore.
Answer» Both (A) and (R ) are CORRECT Both (A) and ( R) are not correct (A) is CORREC but(R ) is WRONG (A) is wrong but (R ) is correct SOLUTION :N/A

Discussion

7503.	Assertion A: Hard water limits the cleaning action of soap. Reason (R ): When combined with soap, hard water develops a thin layer.
Answer» Both (A) and (R ) are correct, (R ) explains (A) (A) is correct but (R ) is wrong (A) is wrong but (R ) is correct Both (A) and (R ) are correct, but (R ) doesn't EXPLAIN (A) Answer :A

Discussion

7504.	Assertion : A greenish layerappears on copper vessels,ifleft uncleaned. Reason : It is due to the formation of layer of bsic copper corbonate .
Answer» Both Assertionand REASON are ture and Reason is correct explanation of Assertion. Both Assertionand Reasonare TRUE but Reason is OT the correct explanation of Assertion. Assertion is true but Reason is false. Assertion is false but reason is true. Answer :A

Discussion

7505.	Assertion (A): Graphite is a good conductor of electricity unlike other non-metals. Reason (R ): Graphite has free electrons in it.
Answer» Both (A) and (R ) are CORRECT (A) is correct but (R ) does not EXPLAIN (A) (A) is WRONG but (R ) is correct Both (A) and (R ) are wrong Answer :A

Discussion

7506.	Assertion (A) : Gold, Silver and Platinum are the metals that are found in free state. Reason (R ) : These metals have low chemical reactivity and are found in free state or in native state.
Answer» Both (A) and (R ) are CORRECT Both (A) and ( R) are not correct (A) is CORREC but(R ) is WRONG (A) is wrong but (R ) is correct SOLUTION :N/A

Discussion

7507.	Assertion (A) : Glucose combines with oxygen in the cells of our body and provides energy. Reason (R) : Reaction in which heat is released along with the formation of products are called exothermic reactions.
Answer» Both (A) and (R) are true and (R) is correct EXPLANATION of the assertion. Both (A) and (R) are true but (R) is not the correct explanation of the assertion. (A) is true but (R) is false. (A) is false but (R) is true. SOLUTION :Both STATEMENTS are correct.

Discussion

7508.	Assertion(A) : Following are the members of a homologous series:CH_(3)OH, CH_(3)CH_(2)OH, CH_(3)CH_(2)CH_(2)OH Reason (R ) : A series of compounds with same functional group but differing by -CH_(2)- unit is called a homologous series.
Answer» Both (A) and (R ) are TRUE and (R ) is correct explanation of the assertion. Both (A) and (R ) are true but (R ) is not the correct explanation of the assertion. (A) is true but (R ) is FALSE. (A) is false but (R ) is true. Solution :Both (A) and (R ) are true and (R ) is correct explanation of the assertion.

Discussion

7509.	Assertion (A) : Fat/Oil containing food substances become rancid and their smell taste changes. Reason (R) : We keep food in air - tight containers.
Answer» Both (A) and (R) are TRUE and (R) is CORRECT EXPLANATION of the assertion. Both (A) and (R) are true but (R) is not the correct explanation of the assertion. (A) is true but (R) is false. (A) is false but (R) is true. Solution :Both the assertion and reason are true STATEMENTS. But reason is not the explanation of assertion.

Discussion

7510.	Assertion (A): Ethanol has much higher boiling point than ethane. Reason (R ): Presence of hydrogen bond in a molecule increase the boiling point.
Answer» Both (A) and (R ) are CORRECT, (R ) EXPLAINS (A) (A) is correct but (R ) is WRONG (A) is wrong but (R ) is correct Both (A) and (R ) are correct, but (R ) doesn't EXPLAIN (A) Answer :A

Discussion

7511.	Assertion (A): Enthalpy of graphite is lower than that of diamond. Reason (R ): Entropy of graphite is greater than that of diamond.
Answer» A and R both are CORRECT, and R is correct EXPLANATION of A A and R both are correct,but R is not the correct explanation of A A is TRUE but R is FALSE A and R both are false.

Discussion

7512.	Assertion (A): Enthalpy of formation of H_(2)O(I) is greater than that of H_(2)O(g). Reason (R ): Enthalpy change is negative for condensation reaction, H_(2)O(g) H_(2)O(I)
Answer» A and R both are CORRECT, and R is correct explanation of A A and R both are correct,but R is not the correct explanation of A A is true but R is FALSE A and R both are false.

Discussion

7513.	Assertion (A): Enthalpy of formation of HCl is equal to bond energy of HCl. Reason (R ): Enthalpy of formation and bond energy both involve the formation of one mole of HCl from the elements.
Answer» A and R both are CORRECT, and R is correct EXPLANATION of A A and R both are correct,but R is not the correct explanation of A A is true but R is FALSE A and R both are false.

Discussion

7514.	Assertion (A): Electroplating method not only protects but also enhances the metallic appearance. Reason (R ) : Electroplating is a method of coating one metal with another by passing current.
Answer» (A) is RIGHT, (R ) is WRONG (A) is right, (R ) is not RELEVANT (A) is right, (R ) are relevant Both (A) and (R ) are wrong SOLUTION :N/A

Discussion

7515.	Assertion (A): Electrovalent compounds are generally insoluble in water.Reason (R) : Copper is lower than aluminium in the reactivity series.
Answer» Both (A) and (R) are TRUE and (R) is correct EXPLANATION of the ASSERTION Both (A) and (R) are true but (R) is not the correct explanation of the assertion. (A) is true but (R) is false. (A) is false but (R) is true. Solution :Assertion is false but reason is true.

Discussion

7516.	Assertion (A): Duralumin is used in making aircraft, tools and pressure cookers. Reason (R): Duralumin is an alloy that is light, strong, resistant to corrosion.
Answer» Both (A) and (R ) are CORRECT Both (A) and ( R) are not correct (A) is CORREC but(R ) is WRONG (A) is wrong but (R ) is correct SOLUTION :N/A

Discussion

7517.	Assertion (A): Diamond is a rigid substance and it is very hard. Reason (R ): In diamond each carbon atom is bonded to three other carbon atoms in the same place giving hexagonal layers held together by weak vander waals forces.
Answer» Both (A) and (R ) are correct (A) is correct but (R ) does not explain (A) Both (A) and (R ) are WRONG (A) is wrong but (R ) is correct Answer :B

Discussion

7518.	Assertion (A) : Delta H and Delta U are same for the reaction N_(2)(g) + O_(2) (g) rarr 2NO(g) Reason (R ): All the reactants and products are gases.
Answer» A and R both are correct, and R is correct EXPLANATION of A A and R both are correct,but R is not the correct explanation of A A is TRUE but R is false A and R both are false.

Discussion

7519.	Assertion (A): Corundum is a chief ore of aluminium. Reaction (R ) : Molecular formula of corundum is Al_(2)O_(3)
Answer» Both (A) and (R ) are CORRECT Both (A) and ( R) are not correct (A) is CORREC but(R ) is WRONG (A) is wrong but (R ) is correct SOLUTION :N/A

Discussion

7520.	Assertion (A): Copper sulphate crystals which seem to be dry contain water of crystallisation.Reason (R) : Plaster of Paris is CaSO_4. (3)/(2)H_2O.
Answer» Both (A) and (R) are true and (R) is correct explanation of the ASSERTION. Both (A) and (R) are true but (R) is not the correct explanation of the assertion. (A) is true but (R) is false. (A) is false but (R) is true. Solution :Plaster of Paris has the formula `CaSO_(4).(1)/(2)H_(2)O`

Discussion

7521.	Assertion (A) :Copper, silver and Gold are used in making coins and jewellery. SO they are called coinage metals. Reason (R ) : These metals release enormous amount of nuclear energy.
Answer» Both (A) and (R ) are CORRECT Both (A) and ( R) are not correct (A) is CORREC but(R ) is WRONG (A) is wrong but (R ) is correct SOLUTION :N/A

Discussion

7522.	Assertion (A) : CO_2 gas is filled in soft drinks using the effect of pressure. Reason (R) : A decrease in pressure increases the solubility of a gas in a liquid.
Answer» Both (A) and (R) are CORRECT Both (A) and (R) are WRONG (A) is correct but (R) is wrong (A) is wrong but (R) is correct Answer :C

Discussion

7523.	Assertion A: Chemical reactivity of the element of group 18 is very less. Reason R: Their outermost shell is completely filled with electrons.
Answer» ASSERTION A and reason R are true, and reason R is the CORRECT explanation of assertion A. Assertion A and reason R are true, but reason R is not the correct explanation of assertion A. Assertion A is CORRET but reason R is false. Assertion A is false but reason R is true. Answer :A

Discussion

7524.	Assertion (A) : Carbon has the ability to form bonds with other carbon atoms, giving rise to large molecules. Reason (R) : Carbon-carbon is a stable bond.
Answer» Both (A) and (R) are TRUE and (R) is correct explanation of the assertion. Both (A) and (R) are true but (R) is not the correct explanation of the assertion. (A) is true but (R) is FALSE. (A) is false but (R) is true. Solution :Both assertion and REASON statements are true and reason is the correct explanation of assertion.

Discussion

7525.	Assertion (A): Carbon compounds hold the key to plant and animal lite on the earth. Reason (R ): Carbon circulates through air, plants, animals and soil by means of complex reactions.
Answer» Both (A) and (R ) are CORRECT Both (A) and (R ) are WRONG (A) is correct but (R ) is wrong (A) is wrong but (R ) is correct Answer :A

Discussion

7526.	Assertion (A): Carbon compounds have low melting and boiling points and they are easily combustible. Reason (R ): Carbon compounds are electrovalent compounds.
Answer» Both (A) and (R ) are CORRECT (A) is correct but (R ) is WRONG Both (A) and (R ) are wrong (A) is wrong but (R ) is correct Answer :B

Discussion

7527.	Assertion (A): Carbon combines with many other elements to form various stable compounds. Reason (R ): The stability of carbon compounds is due to the small size of carbon which enables the nucleus to hold on to the shared pair of electrons strongly.
Answer» Both (A) and (R ) are WRONG Both (A) and (R ) are CORRECT (A) is correct but (R ) is wrong (A) is wrong but (R ) is correct Answer :B

Discussion

7528.	Assertion (A): Carbon chemistry is called as living chemistry. Reason (R ): The carbon atoms form the building blocks of living organisms and carbon combined with other atoms decide life on earth.
Answer» Both (A) and (R ) are WRONG Both (A) and (R ) are CORRECT (A) is correct but (R ) is wrong (A) is wrong but (R ) is correct Answer :B

Discussion

7529.	Assertion (A): C^(4+) cation formationis easy. Reason (R ): Carbon can lose four electrons to form C^(4+) cation require less amount of energy.
Answer» Both (A) and (R ) are CORRECT (A) is WRONG but (R ) is correct (A) is correct but (R ) is wrong Both (A) and (R ) are wrong Answer :D

Discussion

7530.	Assertion (A) : Calcium hydroxide reacts slowly with the CO_(2) in air to form a thin layer of CaCO_(3) on the walls. Reason (R) : Decomposition reactions require energy in the form of heat, light or electricity for breaking down the reactants.
Answer» Both (A) and (R) are TRUE and (R) is correct EXPLANATION of the assertion. Both (A) and (R) are true but (R) is not the correct explanation of the assertion. (A) is true but (R) is false. (A) is false but (R) is true. Solution :Both STATEMENTS are correct.

Discussion

7531.	Assertion (A) : C_(12)H_(22)O_(11) is not a simple ratio. Reason (R ) : The ratio of atoms in a molecule may be fixed and integral but may not be simple.
Answer» Both (A) and (R ) are CORRECT Both (A) and (R ) are WRONG (A) is correct but (R ) is wrong (A) is wrong but (R ) is correct Solution :Both (A) and (R ) are correct

Discussion

7532.	Assertion (A) : Atoms of same element may not similar in all respects. Reason (R ) : Atoms of same element have same atomic number but different number of neutrouns.
Answer» Both (A) and (R ) are CORRECT Both (A) and (R ) are WRONG (A) is correct but (R ) is wrong (A) is wrong but (R ) is correct Solution :Both (A) and (R ) are wrong

Discussion

7533.	Assertion (A): Atoms forming an ionic bond are said to have a give-and-take relation.Reason (R) : The number of shells present in the atom of phosphorus is three.
Answer» Both (A) and (R) are TRUE and (R) is CORRECT EXPLANATION of the assertion Both (A) and (R) are true but (R) is not the correct explanation of the assertion. (A) is true but (R) is false. (A) is false but (R) is true. Solution : Both assertion and REASON are correct but the reason is not the correct explanation of assertion

Discussion

7534.	Assertion (A) : Atoms and molecules are the building blocks of matter. Reason (R ) : Atom is the ultimate particle of an element which may or may or may not have independent existence.
Answer» Both (A) and (R ) are CORRECT Both (A) and (R ) are WRONG (A) is correct but (R ) is wrong (A) is wrong but (R ) is correct Solution :(A) is correct but (R ) is wrong

Discussion

7535.	Assertion (A) : Aqueous copper sulphate is a binary solution. Reason (R) : Copper sulphate solution contains two components i.e., one solute - copper sulphate and one solvent - water.
Answer» Both (A) and (R) are CORRECT Both (A) and (R) are WRONG (A) is correct but (R) is wrong (A) is wrong but (R) is correct Answer :A

Discussion

7536.	Assertion (A) : Aquatic species are more comfortable in cold water.Reason (R): Solubility of oxygen is more in cold water.
Answer» Both (A) and (R) are CORRECT Both (A) and (R) are WRONG (A) is correct but (R) is wrong (A) is wrong but (R) is correct Answer :A

Discussion

7537.	Assertion (A): Antacids are used to get rid of pain caused by indigestion. Reason (R) : Antacids neutralise the excess acid produced in the stomach.
Answer» Both (A) and (R) are true and (R) is correct explanation of the assertion. Both (A) and (R) are true but (R) is not the correct explanation of the assertion. (A) is true but (R) is FALSE. (A) is false but (R) is true. Solution :The REASON EXPLAINS the assertion.

Discussion

7538.	Assertion (A) : Anhydrous calcium chloride is an example of hygroscopic substance. Reason (R) : Anhydrous calcium chloride change its physical state on exposure to air.
Answer» Both (A) and (R) are CORRECT Both (A) and (R) are WRONG (A) is correct but (R) is wrong (A) is wrong but (R) is correct Answer :D

Discussion

7539.	Assertion (A) : An atom is no longer indivisible. Reason (R ) : The sub atomic particles protons, electrons and neuutrons were discovered.
Answer» (A) are (R ) are CORRECT.(R ) EXPLAIN (A) (A) is correct (R ) is WRONG (A) is wrong (R ) is correct (A) and (R ) are correct. (R ) does not explain (A) SOLUTION :(A) are (R ) are correct.(R ) explain (A)

Discussion

7540.	Assertion (A) : An equation is not complete if the physical states of reactants and products is not given. Reason (R) CO_(2) and H_(2)O react in the presence of haemoglobin to produce glucose.
Answer» Both (A) and (R) are TRUE and (R) is CORRECT explanation of the ASSERTION. Both (A) and (R) are true but (R) is not the correct explanation of the assertion. (A) is true but (R) is false. (A) is false but (R) is true. Solution :It should be CHLOROPHYLL and not haemoglobin.

Discussion

7541.	Assertion (A): Among the two O – H bonds in H_(2)O molecule, the energy required to break the first O – H bond and the other O – H bond is the same. Reason (R): This is because the electronic environment around the oxygen is the same even after breakage of one O – H bond.
Answer» A and R both are CORRECT, and R is correct EXPLANATION of A. A and R both are correct, but R is not the correct explanation of A. A is TRUE but R is FALSE. A and R both are false.

Discussion

7542.	Assertion (A) : Alloys are commonlyused in electrical heating devices like electric iron and heater. Reason (R ) : Resistivity of an alloy is generally higher than that of its constituent metals but the alloys have low melting points than their constituent metals.
Answer» Both (A) and (R ) are true and (R ) is correct EXPLANATION of the assertion. Both (A) and (R ) are true but (R ) is not the correct explanation of the assertion. (A) is true but (R ) is false. (A) is false but (R ) is true. Solution :(A) is true but (R ) is false. Reistivity of an ALLOY is GENERALLY HIGHER than that of its constituent metals and the alloys do not oxidize EASILY at high temperatures.

Discussion

7543.	Assertion (A) : All living structures are carbon based. Reason (R) : Carbon compounds are good conductors of electricity.
Answer» Both (A) and (R) are true and (R) is correct explanation of the ASSERTION. Both (A) and (R) are true but (R) is not the correct explanation of the assertion. (A) is true but (R) is false. (A) is false but (R) is true. SOLUTION :Assertion is true but REASON is false.

Discussion

7544.	Assertion (A): Acetic acid has a molecular mass of 50 u. Reason (R) : Food, clothes, medicines, books, etc., contain carbon as an element.
Answer» Both (A) and (R) are true and (R) is CORRECT explanation of the ASSERTION. Both (A) and (R) are true but (R) is not the correct explanation of the assertion. (A) is true but (R) is false. (A) is false but (R) is true. SOLUTION :Both assertion and reason is correct but reason is not the correct explanation of assertion.

Discussion

7545.	Assertion (A) : A complete chemical equation represents the reactants and products and their physical state symbolically. Reason (R) : In a combination reaction, two or more substance combine to form a new single substance.
Answer» Both (A) and (R) are TRUE and (R) is correct EXPLANATION of the assertion. Both (A) and (R) are true but (R) is not the correct explanation of the assertion. (A) is true but (R) is false. (A) is false but (R) is true. SOLUTION :Both the assertion and REASON STATEMENTS are true but reason is not the explanation of assertion.

Discussion

7546.	Assertion (A) : ""_(6)C^(13) and ""_(7)N^(4) are called Isotones. Reason (R ) : Isotones are the atoms of the different element with different atomic number but same mass number.
Answer» Both (A) and (R ) are CORRECT Both (A) and (R ) are WRONG (A) is correct but (R ) is wrong (A) is wrong but (R ) is correct Solution :(A) is correct but (R ) is wrong

Discussion

7547.	Assertion (A) : ""_(6)C^(13) and ""_(7)C^(13) are called isotones. Reason (R ) : Atoms of different elements having the same number of neutrons, but different atomic number and different mass number are called isotones.
Answer» (A) are (R ) are CORRECT.(R ) EXPLAIN (A) (A) is correct (R ) is WRONG (A) is wrong (R ) is correct (A) and (R ) are correct. (R ) does not explain (A) SOLUTION :(A) are (R ) are correct.(R ) explain (A)

Discussion

7548.	Assertion (A) : ""_(18)Ar^(40) and ""_(20)Ca^(40), are isobars. Reason (R ) : They have same atomic mass but different atomic number.
Answer» (A) are (R ) are CORRECT.(R ) EXPLAIN (A) (A) is correct (R ) is WRONG (A) is wrong (R ) is correct (A) and (R ) are correct. (R ) does not explain (A) SOLUTION :(A) are (R ) are correct.(R ) explain (A)

Discussion

7549.	Assertion (A) : ""_(1)H^(1),""_(1)H^(2),""_(1)H^(3) are the isotopes of hydrogen. Reason (R ) : The atoms of same element with same mass number but different at numbers are called isotopes.
Answer» Both (A) and (R ) are CORRECT Both (A) and (R ) are WRONG (A) is correct but (R ) is wrong (A) is wrong but (R ) is correct Solution :(A) is correct but (R ) is wrong

Discussion

7550.	Assertion (A) : 18 g water contains Avogadro number (6.023xx10^(23)) of particles. Reason (R ) : 18 g of water is the molecular mass (or) 1 mole of water. One mole is defined as the amount of the substancewhich contains 6.023xx10^(23) number of particles.
Answer» Both (A) and (R ) are CORRECT Both (A) and (R ) are WRONG (A) is correct but (R ) is wrong (A) is wrong but (R ) is correct Solution :Both (A) and (R ) are correct

Discussion

Explore topic-wise InterviewSolutions in .

Assertion (A) : Hexagonal arrays are placed in layers one above the other in the sctructure of graphite. Reason (R) : Fullerenes form another class of carbon allotropes.

Assertion (A) : Heaematite ore was purified by Hydraulic method. Reason (R ) : Haematite is oxide ore.

Assertion A: Hard water limits the cleaning action of soap. Reason (R ): When combined with soap, hard water develops a thin layer.

Assertion : A greenish layerappears on copper vessels,ifleft uncleaned. Reason : It is due to the formation of layer of bsic copper corbonate .

Assertion (A): Graphite is a good conductor of electricity unlike other non-metals. Reason (R ): Graphite has free electrons in it.

Assertion (A) : Gold, Silver and Platinum are the metals that are found in free state. Reason (R ) : These metals have low chemical reactivity and are found in free state or in native state.

Assertion (A) : Glucose combines with oxygen in the cells of our body and provides energy. Reason (R) : Reaction in which heat is released along with the formation of products are called exothermic reactions.

Assertion(A) : Following are the members of a homologous series:CH_(3)OH, CH_(3)CH_(2)OH, CH_(3)CH_(2)CH_(2)OH Reason (R ) : A series of compounds with same functional group but differing by -CH_(2)- unit is called a homologous series.

Assertion (A) : Fat/Oil containing food substances become rancid and their smell taste changes. Reason (R) : We keep food in air - tight containers.

Assertion (A): Ethanol has much higher boiling point than ethane. Reason (R ): Presence of hydrogen bond in a molecule increase the boiling point.

Assertion (A): Enthalpy of graphite is lower than that of diamond. Reason (R ): Entropy of graphite is greater than that of diamond.

Assertion (A): Enthalpy of formation of H_(2)O(I) is greater than that of H_(2)O(g). Reason (R ): Enthalpy change is negative for condensation reaction, H_(2)O(g) H_(2)O(I)

Assertion (A): Enthalpy of formation of HCl is equal to bond energy of HCl. Reason (R ): Enthalpy of formation and bond energy both involve the formation of one mole of HCl from the elements.

Assertion (A): Electroplating method not only protects but also enhances the metallic appearance. Reason (R ) : Electroplating is a method of coating one metal with another by passing current.

Assertion (A): Electrovalent compounds are generally insoluble in water.Reason (R) : Copper is lower than aluminium in the reactivity series.

Assertion (A): Duralumin is used in making aircraft, tools and pressure cookers. Reason (R): Duralumin is an alloy that is light, strong, resistant to corrosion.

Assertion (A): Diamond is a rigid substance and it is very hard. Reason (R ): In diamond each carbon atom is bonded to three other carbon atoms in the same place giving hexagonal layers held together by weak vander waals forces.

Assertion (A) : Delta H and Delta U are same for the reaction N_(2)(g) + O_(2) (g) rarr 2NO(g) Reason (R ): All the reactants and products are gases.

Assertion (A): Corundum is a chief ore of aluminium. Reaction (R ) : Molecular formula of corundum is Al_(2)O_(3)

Assertion (A): Copper sulphate crystals which seem to be dry contain water of crystallisation.Reason (R) : Plaster of Paris is CaSO_4. (3)/(2)H_2O.

Assertion (A) :Copper, silver and Gold are used in making coins and jewellery. SO they are called coinage metals. Reason (R ) : These metals release enormous amount of nuclear energy.

Assertion (A) : CO_2 gas is filled in soft drinks using the effect of pressure. Reason (R) : A decrease in pressure increases the solubility of a gas in a liquid.

Assertion A: Chemical reactivity of the element of group 18 is very less. Reason R: Their outermost shell is completely filled with electrons.

Assertion (A) : Carbon has the ability to form bonds with other carbon atoms, giving rise to large molecules. Reason (R) : Carbon-carbon is a stable bond.

Assertion (A): Carbon compounds hold the key to plant and animal lite on the earth. Reason (R ): Carbon circulates through air, plants, animals and soil by means of complex reactions.

Assertion (A): Carbon compounds have low melting and boiling points and they are easily combustible. Reason (R ): Carbon compounds are electrovalent compounds.

Assertion (A): Carbon combines with many other elements to form various stable compounds. Reason (R ): The stability of carbon compounds is due to the small size of carbon which enables the nucleus to hold on to the shared pair of electrons strongly.

Assertion (A): Carbon chemistry is called as living chemistry. Reason (R ): The carbon atoms form the building blocks of living organisms and carbon combined with other atoms decide life on earth.

Assertion (A): C^(4+) cation formationis easy. Reason (R ): Carbon can lose four electrons to form C^(4+) cation require less amount of energy.

Assertion (A) : Calcium hydroxide reacts slowly with the CO_(2) in air to form a thin layer of CaCO_(3) on the walls. Reason (R) : Decomposition reactions require energy in the form of heat, light or electricity for breaking down the reactants.

Assertion (A) : C_(12)H_(22)O_(11) is not a simple ratio. Reason (R ) : The ratio of atoms in a molecule may be fixed and integral but may not be simple.

Assertion (A) : Atoms of same element may not similar in all respects. Reason (R ) : Atoms of same element have same atomic number but different number of neutrouns.

Assertion (A): Atoms forming an ionic bond are said to have a give-and-take relation.Reason (R) : The number of shells present in the atom of phosphorus is three.

Assertion (A) : Atoms and molecules are the building blocks of matter. Reason (R ) : Atom is the ultimate particle of an element which may or may or may not have independent existence.

Assertion (A) : Aqueous copper sulphate is a binary solution. Reason (R) : Copper sulphate solution contains two components i.e., one solute - copper sulphate and one solvent - water.

Assertion (A) : Aquatic species are more comfortable in cold water.Reason (R): Solubility of oxygen is more in cold water.

Assertion (A): Antacids are used to get rid of pain caused by indigestion. Reason (R) : Antacids neutralise the excess acid produced in the stomach.

Assertion (A) : Anhydrous calcium chloride is an example of hygroscopic substance. Reason (R) : Anhydrous calcium chloride change its physical state on exposure to air.

Assertion (A) : An atom is no longer indivisible. Reason (R ) : The sub atomic particles protons, electrons and neuutrons were discovered.

Assertion (A) : An equation is not complete if the physical states of reactants and products is not given. Reason (R) CO_(2) and H_(2)O react in the presence of haemoglobin to produce glucose.

Assertion (A): Among the two O – H bonds in H_(2)O molecule, the energy required to break the first O – H bond and the other O – H bond is the same. Reason (R): This is because the electronic environment around the oxygen is the same even after breakage of one O – H bond.

Assertion (A) : Alloys are commonlyused in electrical heating devices like electric iron and heater. Reason (R ) : Resistivity of an alloy is generally higher than that of its constituent metals but the alloys have low melting points than their constituent metals.

Assertion (A) : All living structures are carbon based. Reason (R) : Carbon compounds are good conductors of electricity.

Assertion (A): Acetic acid has a molecular mass of 50 u. Reason (R) : Food, clothes, medicines, books, etc., contain carbon as an element.

Assertion (A) : A complete chemical equation represents the reactants and products and their physical state symbolically. Reason (R) : In a combination reaction, two or more substance combine to form a new single substance.

Assertion (A) : ""_(6)C^(13) and ""_(7)N^(4) are called Isotones. Reason (R ) : Isotones are the atoms of the different element with different atomic number but same mass number.

Assertion (A) : ""_(6)C^(13) and ""_(7)C^(13) are called isotones. Reason (R ) : Atoms of different elements having the same number of neutrons, but different atomic number and different mass number are called isotones.

Assertion (A) : ""_(18)Ar^(40) and ""_(20)Ca^(40), are isobars. Reason (R ) : They have same atomic mass but different atomic number.

Assertion (A) : ""_(1)H^(1),""_(1)H^(2),""_(1)H^(3) are the isotopes of hydrogen. Reason (R ) : The atoms of same element with same mass number but different at numbers are called isotopes.

Assertion (A) : 18 g water contains Avogadro number (6.023xx10^(23)) of particles. Reason (R ) : 18 g of water is the molecular mass (or) 1 mole of water. One mole is defined as the amount of the substancewhich contains 6.023xx10^(23) number of particles.