InterviewSolution
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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 101. |
You are provided with two aqueous solutions X and Y of equal molar concentrations . How willyou test which one contains strong electrolyte and which one contains weak electrolyte ? |
Answer» Solution :When the same CURRENT is passed through the solution Y , the intensity of glow of the bulb is low . THEREFORE , solution Y containsa WEAK electrolyte . 
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| 102. |
Which of the following is a physical change ? |
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Answer» BURNING of natural gas |
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| 103. |
Which one of the following metals is most ductile? |
| Answer» SOLUTION :Gold | |
| 104. |
The volume of a gas at a given temperature and pressure is proportional to the number of particles. |
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Answer» |
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| 105. |
What is meant by the statement that the rating of fuse in a ciruit is 5A. |
| Answer» SOLUTION :It MEANS maximum current of 5A can pass through the fuse WITHOUT MELTING it. | |
| 106. |
Which elementexhibits thepropertyof catenationtomaximum extentand why? |
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Answer» |
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| 107. |
What are structural isomers ? Draw two structural isomers of butane. |
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Answer» Solution :MOLECULES that have same chemical formula but DIFFERENT spatial ARRANGEMENT of their constituent atoms are called STRUCTURAL isomers. The isomers of butane are: `underset(C_4H_10)underset("Butane")(H-underset(H)underset(|)OVERSET(H)overset(|)(C )-underset(H)underset(|)overset(H)overset(|)(C )-underset(H)underset(|)overset(H)overset(|)(C )-underset(H)underset(|)overset(H)overset(|)(C )-H) "" underset(C_4H_10)underset("Isobutane")(H-underset(H)underset(|)overset(H)overset(|)(C )-underset(H)underset(|)underset(H-C-H)underset(|)overset(H)overset(|)(C )-underset(H)underset(|)overset(H)overset(|)(C )-H` |
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| 108. |
Which of the following are alkenes? CH_(4), C_(2)H_(6), C_(2)H_(4), C_(3)H_(6) and C_(3)H_(8). |
| Answer» Solution :`C_(2)H_(4) and C_(3)H_(6)` are ALKENES. | |
| 109. |
Which of the following pairs will give displacement reactions? (a). NaCl solution and copper metal (b). MgCl_(2) solution and aluminium metal. (c). FeSO_(4) solution and silver metal. (d). AgNO_(3) solution and copper metal. |
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Answer» Solution :(a). Copper metal is less reactive than sodium metal (Na), so no displacement reaction will occur between NaCl solution and copper metal. (b). ALUMINIMUM metal is less reactive than magnesium metal (Mg). So no displacement reaction will take place between `MgCl_(2)` solution and aluminium metal. (c). silver metal is less reactive than IRON metal (Fe), so no displacement reaction will occur between `FeSO_(4)` solution and silver metal. (d) Copper metal is more reactive than silver metal (Ag), soadisplacement reaction will take place between `AgNO_(3)` solution and copper metal. |
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| 110. |
Which of the following is a mixture ? |
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Answer» Air |
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| 111. |
What is reflex are ? |
| Answer» SOLUTION :The STRUCTURAL and functional unit that carries out reflex action is CALLED a reflex ARC. | |
| 112. |
What happens during a chemical reaction? |
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Answer» Solution :i.In a chemical REACTION,the ATOMS of the reacting molecules or elements are rearranged to form new molecules. ii.Old chemical BONDS between atoms of the reacting molecules or elements are rearranged to form new molecules. iii.Bond BREAKING ABSORBS energy whereas bond formation releases energy. |
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| 113. |
Whichof the followinginformationis notconveyedbya balancedchemical equation ? |
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Answer» physicalstatesof reactantsand products |
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| 114. |
Write the effect of dilute hydrochloric acid on the colour of the following indicators: Phenolphthalein |
| Answer» SOLUTION :No EFFECT | |
| 115. |
What are the smallest particles of matter called? |
| Answer» SOLUTION :The smallest particles of matter are CALLED ATOMS and molecules. | |
| 117. |
Which of the following statement(s) is (are) wrong ? |
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Answer» METHANE cannot undergo addition reactions . |
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| 118. |
Zinc dissolved in copper is an example of ................... solution. |
| Answer» SOLUTION :SOLID in solid | |
| 119. |
What is an aqua regia ? Which metals can be dissolved in it ? |
| Answer» Solution :A freshly prepared MIXTURE of concentrated HYDROCHLORIC acid and concentrated nitric acid in the ratio of 3:1 is called an aqua REGIA (Latin meaining .royal water.). Aqua regia is a highly corrosive, fuming LIQUID. Many metals along with noble metals like gold and platinum can be DISSOLVED in aqua regia solution. | |
| 120. |
Which of the following properties is different for solids, liquids and gases? |
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Answer» MOVEMENT of MOLECULES |
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| 121. |
Write two observations that you will make when an iron nail is kept in an aqueous solution of copper sulphate. Write the chemical equations for this reactions. |
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Answer» Solution :Blue colour changes to light green. Reddish brown deposit on the iron nail. `Fe(s) + CuSO_(4)(AQ) rarr FeSO_(4)(aq) + CU(s)` |
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| 122. |
When iron is exposed to moist air, a reddish brown substance is deposited on it. What is it ? Give its composition. |
| Answer» SOLUTION :HYDRATED FERRIC OXIDE - RUST `Fe_2O_3 xH_2O`. | |
| 123. |
What are alloys? |
| Answer» Solution :Alloys are HOMOGENEOUS mixtures of two or more metals, or a metal and a non metal . For example,BRASS is an alloy of two metals- copper and zinc, WHEREAS steel is an alloy of a metal, iron and a small AMOUNT of a non metal, carbon. | |
| 124. |
Which is rust ? Give the equation for formation of rust. |
| Answer» Solution :When iron is exposed to moist air, it FORMS a LAYER of brown hydrated ferric oxide on its surface. This compound is known as rust and the pehnomenon of FORMATION of rust is known as rusting `4Fe + 3O_(2) + x H_(2)O to 2Fe_(2)O_(3). xH_(2)O` | |
| 125. |
What are the main classs of decomposition reactions? |
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Answer» SOLUTION :There are three MAIN CLASSES of decomposition REACTIONS.The are, i.Thermal decomposition reactions ii.Electrilytic decomposition reactions . iii.Photo decomposition reactions. |
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| 126. |
The soil in a field in highly acidic. List any two materials which can be added to this soil to reduce its acidity. Give the reason for your choice. |
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Answer» SOLUTION :(i) LIME (CaO) calcium OXIDE is added to NEUTRALISE its acidity. (ii) Chalk `(CaCO_(3))` calcium carbonate can also be added to neutralise its acidity. This is because both CaO and `CaCO_(3)` are basic in nature which neutralise acid present in SOIL. |
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| 127. |
Which products are obtained when metals react with water ? Explain the reaction of metals such as potassium (K), sodium (Na). calcium (Ca), magnesium (Mg), aluminium (Al), iron (Fe), zinc (Zn), lead (Pb), copper (Cu), silver (Ag) and gold (Au) with water. |
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Answer» SOLUTION :Metals react with water and produce a metal oxide and hydrogen gas.Metal oxides are soluble in water and form metal hydroxide. Metals LIKE potassium and sodium react violently with cold water and the evolved hydrogen gas which catches fire immediately. `2K(s) + 2H_2O(l) to 2KOH(aq) + H_2(g) `+ Heat energy `2Na(s) + 2H_2O(l) to 2NaOH(aq) + H_2(g) ` + heat energy The reaction of calcium with water is less violent. The heat evolved during the reaction is not sufficient for the hydrogen gas to catch fire. ` Ca(s) + 2H_2O(l) TOCA(OH)_2(aq) + H_2(g)` Calcium starts floating because the bubbles of hydrogen gas formed stick to the surface of metal.Magnesium does not react with cold water but it reacts with hot water to form magnesium hydroxide and hydrogen gas. ` Mg(s) + underset("hot")(2H_2O(l)) to Mg(OH)_2 (aq) + H_2(g)` Magnesium starts floating due to the bubbles of hydrogen gas sticking to its surface. Metals like ALUMINIUM, iron and zinc do not react either with cold or hot water, but they react with steam to form metal oxide and hydrogen gas. `2Al(s) + 3H_2O(g)toAl_2O_3(s) + 3H_2(g)` `3Fe(s)+ 4H_2O(g) to Fe_3O_4(s) + 4H_2(g)` Metals such as lead, copper, silver and gold do not react with water at all. |
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| 128. |
What are the names of compounds? CH_(3)-CH_(2)-Br |
| Answer» SOLUTION :BROMETHANE or ETHYL BROMIDE. | |
| 129. |
While cooking , if the bottom of the vessel is getting blackened on the outside, it means that |
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Answer» food is not cooked COMPLETELY |
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| 130. |
Which of the following can lose two electrons to attain the configuration of argon? |
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Answer» Mg <BR>Br can LOSE two ELECTRONS to ATTAIN an electronic configuration of `""_(18)Ar-underset(2)K""underset(8)L""underset(8)M` |
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| 131. |
What are the names of compounds? H-underset(H)underset(|)overset(H)overset(|)C-underset(H)underset(|)overset(H)overset(|)C-underset(H)underset(|)overset(H)overset(|)C-underset(H)underset(|)overset(H)overset(|)C-C-=C-H |
| Answer» SOLUTION :HEXYNE. | |
| 132. |
Translate thestatements into chemical equations and then balance them: Hydrogen sulphide gas burns in air to give water and sulphur dioxide. |
| Answer» Solution :`underset("Hydrogen sulphide")(2H_(2)S(G))+ underset("Oxygen")(3O_(2)(g)) tounderset("SULPHUR DIOXIDE")(2SO_(2)(g))+ underset("WATER")(2H_(2)O(I))` | |
| 133. |
Upto which element, the Law of Octaves was found to be applicable ? |
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Answer» Oxygen |
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| 134. |
Who classified the elements on the basis of fundamental properties of elements like atomic mass? |
| Answer» SOLUTION :MENDELEEV | |
| 135. |
What is meant by Dobereiner's triads? Explain. |
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Answer» Solution :Johann Wolfgang Dobereiner, a German chemist tried to arrange the elements with similar properties into GROUPS. He identified some groups having THREE elements each. These groups of three elements were called triads. Law of triads : When the three elements in a triad were arranged in the order of INCREASING atomic masses, the atomic mass of the middle element is roughly the average of the atomic masses of the other TWO elements. For example, lithium (Li), SODIUM (Na) and potassium (K) constitute a triad. The atomic masses of Li, Na and Kare 6.9 u, 23.0 u and 39.0 u respectively. The atomic mass of middle element, sodium (Na) is roughly the average of the atomic masses of lithium (Li) and potassium (K).  Average of atomic masses of Li and `K=(6.9+39)/(2)=22.95~=23.0u` Dobereiner.s triads are as follows: 
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| 136. |
What happens when a cold and concentrated solution of sodium chloride reacts with ammonia and carbon dioxide ? Write the equation of the reaction which takes place |
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Answer» Solution :When a cold and concentrated solution of SODIUM chloride reacts with ammonia and carbon dioxide , sodium hydrogencarbonate (baking soda) and ammonium chloride is formed. `NACL +NH_(3) +H_(2)O+CO_(2)rarr UNDERSET("Baking soda") (NaHCO_3)+NH_(4)CL` |
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| 137. |
Which of the following defects decrease the density ? |
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Answer» Intersitital defect |
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| 138. |
What would be the pH of an aqyeous solution of sulphuric acid which is 5xx10 ^(-5) mol litre^(-1) in concentration. |
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Answer» SOLUTION :Sulphuric acid dissociates in water as: `H_(2)SO_(4(aq))to2H_(aq)^(+)+SO_(4(aq))^(2-)` Each mole of sulphuric acid gives TWO m oles of `H^(+)` in the solution .One litre of `H_(2)SO_(4)` Solution contains `5xx10^(-5)` moles of `H_(2)SO_(4)` which WOULD GIVE `2xx5xx10^(-5)=10xx10^(-5)` pr `1.0xx10^(-4)` ,moles of `H^(+)` ion in on litre of the solution. Therefore ,`[H^(+)]=1.0xx10^(-4)` mol `litre^(-1)` pH=`-log[H^(+)]=-log_(10)10^(-4)=-(-4xxlog_(10)10)` `-(-4xx1)=4` |
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| 139. |
Which of thefollowing pairs of gasescorresponds to theratio of therates of diffusion as sqrt2 : 1? |
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Answer» `H_(2) and He` |
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| 140. |
What is the process called in which an acid reacts with a base to produce salt and water ? |
| Answer» SOLUTION :NEUTRALIZATION . | |
| 141. |
Which one is a nonelectrolyte ? |
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Answer» Liquid CARBON tetrachloride |
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| 142. |
Using the above table, answer the following questions: (i) Which element will form only covalent compounds ? (ii) Which element is a metal with valency 3 ? (iii) Which element is a non-metal with valency 3 ? (iv) Out of D and E, which one has a bigger atomic size? (v) Write common name for the family of elements, C and E |
| Answer» Solution :(i) E (11) D (III) B (IV) D (v) INERT gases or noble gases | |
| 143. |
Which element has (a) two shells, both of which are completely filled with electrons ? (b) the electronic configuration 2, 8, 2? (c) a total of three shells, with four electrons in its valence shell? (d) twice as many electrons in its second shell as in its first shell ? |
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Answer» Solution :(a) Neon. It has two shells with configuration 2, 8. Thus, both these shells are completely filled. (b) Magnesium. It has the atomic mass 24 and atomic number 12. Electronic configuration is 2, 8, 2. (c) The element has three shells in all, with four electrons in the OUTERMOST SHELL. Thus, the electronic configuration is 2, 8, 4. It corresponds to silicon. (d) Maximum CAPACITY of FIRST shell is 2. Thus, the second shell contains `2 xx 2 = 4` electrons. Thus, the electronic configuration is 2, 4. This configuration corresponds to carbon. |
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| 144. |
Write the chemical reaction taking place between lead nitrate and potassium iodide. Identify the type of reaction. |
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Answer» SOLUTION :Equation for reaction : `PB(NO_(3))_(2)(s)+2Kl(s) to Pbl_(2)(aq) +2KNO_(3)(aq)` It is a double displacement reaction. |
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| 145. |
What is meant by saturated and unsaturated carbon compounds ? |
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Answer» Solution :Saturated carbon compounds : Compounds of carbon having only SINGLE BONDS between the carbon atoms are known as saturated carbon compounds. Unsaturated carbon compounds : Compounds of carbon having DOUBLE or triple bonds between the carbon atoms are known as unsaturated cabon compounds. Unsaturated carbon compounds are more REACTIVE than saturated carbon compounds. |
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| 146. |
What is ' blue vitriol ? |
| Answer» SOLUTION :It is the COMMON name of copper silphate pentahydrate ` (CuSO_(4) . 5H_(2)O` ) | |
| 147. |
What is the nature of non - metal oxide? |
| Answer» SOLUTION :Non-metal OXIDES are ACIDIC or NEUTRAL in NATURE. | |
| 148. |
What are the two properties of carbon which leads which lead to the huge number of carbon compounds we see around us? |
| Answer» SOLUTION :Catention and TETRAVALENCY . | |
| 149. |
What are the substances on the left of the arrow (to) in a chemical equation called ? |
| Answer» SOLUTION :REACTANTS | |
| 150. |
Write the name of the products obtained and type of reaction given below: Na_(2)SO_(4)+BaCl_(2) to ……+…. |
| Answer» Solution :`Na_(2)SO_(4)+ BaCl_(2) to underset("BARIUM SULPHATE")(BaSO_(4))+ underset("SODIUM Chloride")(2NaCl)` | |