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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.
| 1151. |
What is the common name of ethanoic acid ? How ethanoic acid is different from vinegar ? Give the use of vinegar in our daily life. |
| Answer» Solution :Ethanoic acid `(CH_(3)COOH)` is COMMONLY known as acetic acid. The dilute solution of acetic acid in WATER (6-8%) is known as vinegar. The vinegar is used for PRESERVING FOOD SAUSAGE, pickles, etc. | |
| 1152. |
What are ores ? |
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Answer» Solution : The MINERAL from which a metal can be readily and econimically EXTRACTED on a large scale is said to be an ore . e.g BAUXITE `Al_(2)O_(3)`.`2H_(2)O` is the ore of Aluminium |
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| 1153. |
What were the limitations of Dobereiner's classification ? |
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Answer» Solution :The limitations of Dobereiner.s classification are as follows: (1) All the ELEMENTS known at that time could not be arranged as Dobereiner.s TRIAD. Hence this method of classification of elements into triads was not found to be successful. (2) Three elements NITROGEN (N), phosphorus 3 (P) and arsenic (As) were then known elements, but these elements could not be CLASSIFIED as Dobereiner.s triad. |
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| 1155. |
Which of the following substance will not give carbon dioxide on treatment with dilute acid ? |
| Answer» Solution :Lime | |
| 1156. |
Whichamongthe followingchemical reactionis anexampleof combinationreaction ? (i)H_(2(g))+Cl_(2(g)) to2HCl_((g)) (ii)NaOH_((aq))+HCl_((aq))+H_(2)O_((l)) (iii )2Mg_((s)) +O_(2(g))to 2MgO_((s)) (Iv ) Zn_((s))+2HCl_((aq)) toZnCl_(2) +H_(2(g)) |
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Answer» Only(i) |
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| 1157. |
What is Geothermal energy? How can it be harnessed to produce electrical energy. |
| Answer» Solution :The energy obtained from the earth.s crust is called Geothermal energy When underground WATER COMES in CONTACT with hot spots, STEAM is GENERATED. The steam is taken out through pipe to a turbine to produce electricity. | |
| 1158. |
What is observed after about I hour of adding strips of Cu and Al suspended in FeSO_(4) solution in two beakers. Name the reaction and change observed. Also write the chemical equations. |
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Answer» Solution :When `Cu` strip is suspended in `FeSO_(4)` solution, no reaction takes place. When Al strip is suspended in `FeSO_(4)` solution the pale GREEN COLOUR becomes colourless and grayish black iron metal will deposit on ALUMINIUM strip `2Al(s)+3FeSO_(4)(aq)toAl_(2)(SO_(4))_(3)(aq)+3Fe(s)`. |
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| 1159. |
Which gas is produced, when dilute hydrochloric acid is added to a reactive metal?Write the chemical equation , when iron reacts with dilute H_2SO_4? |
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Answer» Solution :Hydrogen gas is PRODUCED, when a metal reacts with dilute hydrochloric acid `M(s)_(Met al)+2HCL(aq)_(Hydrochloric acid (Dilute))to MCl_2(s)_(Met al Chloride)+H_2(g)_(HYDROG en)` Chemical equation for the reaction of iron with dilute `H_2SO_4` is `Fe(s)_(Met al)+ H_2So_4(aq)_(Dilute su lphuric acid ) to FeSo_4(aq)_(Iron II su lpha te)+H_2(g)_(Hydrog en)` |
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| 1160. |
Which of the following molecule can undergo addition reaction? |
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Answer» methane |
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| 1161. |
Whathappens duringa chemicalchange? |
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Answer» SOLUTION :(i) Ina chemicalreactionreaction, the atomsofthe reactingmoleculesor ELEMENTS arerarrangedtoformnewmolecules . (ii)Oldchemicalbondsbetweenatomsarebroken and newchemicalbondsare formed . (III )Bondbreaking absorbsenergywhereasbondformationreleasesenergy . |
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| 1162. |
Which of the following compounds is an acids? |
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Answer» `Na_(2)O` |
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| 1164. |
When molten sodium chloride (NaCI) is electrolysed, the gas liberated at the anode is……………. |
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Answer» |
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| 1165. |
What is an oxidising agent? What happens when an oxidising agent is added to propanol ? Explain with the help of a chemical equation. |
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Answer» SOLUTION :(i) It is a SUBSTANCE which can GIVE oxygen to other substances. `CH_(3)-CH_(2)-CH_(2)-Oh overset("Alkaline "KMnO_(4)+"Heat")UNDERSET("Acidified "KCr_(2)O^(-)"+Heat")rightarrow` Propanol  (iii) Propanol is oxidised to Propanoic acid. |
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| 1166. |
What do you mean by precipitation reactions? Explain giving examples. |
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Answer» Solution :On mixing the clear SOLUTIONS of two ionic compounds, a substance which is insoluble in water, is formed. This insoluble substance formed is known as precipitate. Any REACTION that produces a precipitate is CALLED a precipitation reaction. When sodium sulphate solution is mixed with barium chloride solution, a white substance `BaSO_(4)` is formed. `Na_(2)SO_(4)(aq)+BaCl_(2)(aq)rarrBaSO_(4)(s)darr+2NaCl(aq)` The white precipitate of `BaSO_(4)` is formed by the reaction of `SO_(4)^(2-)ANDBA^(2+)`. The other product formed is sodium chloride which remains in the solution. |
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| 1167. |
Which one of the following solutions will turn red litmus blue? |
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Answer» LEMON juice |
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| 1168. |
Which of the following represent N, molecules |
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Answer» `UNDERSET(""_(X)^(X )N-=N_(X)^(X))` |
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| 1169. |
Write the effect of dilute hydrochloric acid on the colour of the following indicators: Red litmus |
| Answer» SOLUTION :No CHANGE | |
| 1170. |
Write the name of apparatus/chemicals required to study the following properties of ethanoic acid in the laboratory. Nature, odour, solubility and action are sodium hydrogen carbonate. |
| Answer» Solution :LITMUS paper, test tube, test tube, LIME water. For details, consult Chapter 4 (Section 4.17). | |
| 1171. |
What are hydrocarbon compounds ? Explain its classification. |
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Answer» Solution :COMPOUNDS which consist of only two ELEMENTS of carbon and hydrogen are called hydrocarbon compounds. The classification of hydrocarbon compounds are as follows:  Alkanes : Hydrocarbon compounds in which only single bond exist between carbon-carbon ATOMS are known as alkanes. For example, butane, pentane, HEXANE, etc. Alkenes : Hydrocarbon compounds which contain one or more carbon-carbon double BONDS between two carbon atoms are known as alkenes. For example, butene, pentene, hexene, etc. Alkynes : Hydrocarbon compounds which contain one or more carbon-carbon triple bonds between two carbon atoms are known as alkynes. For example, butyne, pentyne, hexyne, etc. |
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| 1172. |
When hydrogen gas is passed over heated copper oxide ,copper and steam are formed. Write the balanced chemical equation with physical states. State what kind of chemical reaction is this. |
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Answer» SOLUTION :(i) `CUO(s)+H_(2)(g)TOCU(s)+H_(2)O(g)` (ii) This is REDOX reaction |
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| 1173. |
What is an olfactory indicator ? Name two such indicators. |
| Answer» SOLUTION :Those SUBSTANCES whose smeel (or odour) changes in acidic or BASIC solutions are called olfactory INDICATORS. ONION and vanilla extract are olfactory indicators. | |
| 1174. |
X' is a compound used in cough syrups and in many tonics. It is soluble in H2O i) Name the compound X. Write its chemical forumula. ii) Which gas is evolved when compound X reacts with Sodium? How will you test the chemical equation involved in the reaction of X with sodium. iii) Complete the following equation for X and identify Y. X overset("heat")(rarr)Y. |
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Answer» Solution :i] The COMPOUND .X. is ETHANOL its chemical formula is `CH_3 - CH_2OH [C_2H_5OH]` ii] Hydrogen gas is evolved when ethanol reacts with sodium. On bringing a burning MATCHSTICK near to the gas, it BURNS with a pop sound. The equation is `2C_2H_5OH + 2Na to 2 C_2H_5O^(-)Na^(+) + H_2 uarr` iii] `underset(X)(CH_3CH_2OH)underset("HEAT")overset("Alk KMnO_4)(rarr) underset(Y)(CH_3COOH)` The compound .Y. is ethanoic acid. |
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| 1175. |
The volume occupied by 14 g of Nitrogen gas is 22.4 litres. |
| Answer» SOLUTION :Correct STATEMENT : The volume OCCUPIED by 14 g of Nitrogen gas is 11.2 LITRES. | |
| 1176. |
The resistance of a conductor is 27 . If it is cut into three equal parts and connected in parallel, them its total resistance is |
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Answer» `6 Omega` |
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| 1177. |
What is a neutralisation reaction ? Give two examples. |
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Answer» SOLUTION :The INTERACTION of an acid with a base to form salt and water is called neutralisation reaction. Examples : `underset("Hydrochloric acid")(HCl) + underset("Sodium hydroxide")(NaOH) to underset("Sodium CHLORIDE")(NaCl) + underset("Water")(H_2O)` `underset("Nitric acid ")(HNO_3) + underset("Potassium hydroxide")(KOH) to underset("Potassium nitrate")(KNO_3) + underset("water")(H_2O)` |
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| 1179. |
What would be the electron-dot structure of carbon dioxide which has the formula of CO_2? |
Answer» SOLUTION :
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| 1180. |
What happens when A mixture of ethyl alcohol, acetic acid and conc. H_2 SO_4 is heated. |
| Answer» SOLUTION :`C_2H_5OH + CH_3COOH OVERSET(conc.H_2SO_4)(to) CH_3COOC_2H_5 + H_2O` | |
| 1182. |
Which one of the following is a member of halogen family? |
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Answer» Cu |
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| 1183. |
Two elements 'X' and 'Y' belong to the second group of the Periodic Table. 'X' has 2 shells and 'Y' has 3 shells in it. (a) Which of these is more metallic in nature and why? (b) What is the formula of the chloride of 'X' and sulphide of 'Y' ? (c) Is the valency of 'X' same as that of 'Y' or different? Why? |
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Answer» Solution :(a) Y is more metallic in NATURE. As we move down the group, the valence ELECTRONS get farther from the NUCLEUS. The hold of the nucleus on the valence electrons decreases. Thus electrons can be removed more easily. In other words, metallic character increases down the group. `XCI_2` and YS (c ) X has the same valency as Y which is EQUAL to 2. This is because both have 2 electrons in the valence SHELL. |
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| 1184. |
Write the structural formula of functional groups (i) aldehyde, (ii) ketone and (iii) carboxylic acid respectively. |
| Answer» SOLUTION :(i)`-UNDERSET(O)underset(||)C-H` (II)`-underset(O)underset(||)C-` (III)`-underset(O)underset(||)C-OH` | |
| 1185. |
X' grams each of nitrogen and carbon monoxide are considered. Draw a compartion with respectto number of moles. |
| Answer» Solution :NITROGEN and carbon monoxide possess equal GRAM molecular mass. THEREFORE, equal MASSES of these two gases possess equal number of moles. | |
| 1186. |
What do you mean by Electron affinity ? How it varies in group and periods in modern periodic table? |
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Answer» Solution :The tendency of an element is to gain an additional electron. This ability is measured by electron AFFINITY. It is the energy CHANGE when an electron is accepted by an atom in the gaseous state. Electron affinity is asigned positive VALUE when energy is released during the process. Greater the value of electron affinity, more energy is released during the process and greater is the tendency of the atom to gain electron In a GROUP, the electron affinity decreases on moving from top to bottom as less and less amount of energy is released. In a period, the electron affinity INCREASES from left to right as more and more amount of energy is released |
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| 1187. |
Two elements 'P' and 'Q' belong to the same period of the modern periodic table and are in Group -1 and Group -2 respectively. Compare their following characteristics in tabular form: (i) The number of electrons in their atoms (ii) The sizes of their atoms (iii) Their metallic characters (iv) Their tendencies to lose electrons (v) The formula of their oxides (vi) The formula of their chlorides |
Answer» SOLUTION :
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| 1188. |
What is anodising ? How is it used to prevent aluminium from corrosion ? |
| Answer» Solution :ANODISING is a process of forming a thick OXIDE layer of aluminium. During anodising, a CLEAN aluminium article is made the anode and is electro-lyses with dilute `H_(2)SO_(4)`. The oxygen liberated at the anode reacts with aluminium to produce a thick protective oxide layer on its SURFACE. | |
| 1189. |
Where do compounds of carbons find applications ? |
| Answer» Solution :The CARBON COMPOUNDS are being INCREASINGLY used as a sourcce of ENERGY as medicines, colours, textiles, PLASTICS, food preservatives, etc. | |
| 1190. |
Write the changes observed on addition of the reagents (a) and (b) to the hydrocarbons (i), (ii) and (iii).Reagents: (a) ammoniacal copper (1) chloride solution(b) alkaline potassium permanganate solutionHydrocarbons: (i) ethane (ii) ethene (iii) ethyne |
| Answer» Solution :(i)ETHANE: No reaction with reagents (a) and (b (ii) Ethene: DECOLOURISES reagent (b) but no reaction with reagent (a) (iii) ETHYNE: GIVES red precipitate with reagent (a), and decolourises reagent (b) | |
| 1191. |
Three solutions of zinc sulphate, magnesium sulphate and aluminium sulphate are prepared in laboratory by a lab assistant. But he forgot to label the reagent bottles. How will you label these bottles by using the metal reactivity studies ? |
| Answer» Solution : Take three test tubes and add LITTLE amount of each solution from the reagent bottle separately. Drop a small PIECE of magnesium in it. The test tube in which there is no reaction contains magnesium SULPHATE. Now, to identify the remaining TWO SOLUTIONS, take these two solutions in two different test tubes and add a small piece of aluminium metal to them. The test tube in which, there is no reaction contains aluminium sulphate and the other one is zinc sulphate. | |
| 1192. |
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. |
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Answer» (i)only |
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| 1193. |
Which element hastwice as many electrons in its second shell as in its first shell? |
| Answer» SOLUTION :C (2, 4) | |
| 1194. |
Which one of these has higher concentration of H^(+) ions ? 1 M HCl or 1M CH_(3)COOH |
| Answer» Solution :1 M HCL has a HIGHER CONCENTRATION of `H^(+)` ions because it is a stronger acid than `CH_(3)COOH.` | |
| 1195. |
Write the equation of the reaction that occurs when CaO is treated with HCl. |
| Answer» Solution :`CAO + 2HCI to CaCl_(2) + H_(2)O` | |
| 1196. |
What should we do when someone is stung by the leaves of a nettle plant ? |
| Answer» SOLUTION :The AFFECTED part of the skin is RUBBED with the leaves of a dock plant. | |
| 1197. |
Write the balanced equations of reaction of magnesium, aluminium, zinc and iron with dilute sulphuric acid. |
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Answer» Solution :`MG(s) + H_2SO_4(aq) to MgSO_4(aq) + H_2(G)` `2Al(s) + 3H_2SO_4(aq) to Al_2(SO_4)_3(aq) + 3H_2(g) ` `ZN(s) + H_2SO_4(aq) to ZnSO_4(aq) + H_2(g)` `FE(s) + H_2SO_4 (aq) to FeSO_4(aq) + H_2(g) ` |
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| 1198. |
Which of the following is spread on icy roads to melt ice in cold countries? |
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Answer» Sodium bicarbonate |
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| 1199. |
What were the criteria used by Mendeleev in creating his Periodic Table? |
| Answer» Solution :When Mendeleev started his work, 63 elements were known. He tried PUTTING the elements in orderof their atomic masses. He also examined the relationship between the atomic masses of the elements and their physical and chemical properties. Among chemical properties, Mendeleev concentrated on the compounds formed by elements with oxygen and hydrogen. He SELECTED hydrogen and oxygen as they are very reactive and formed compounds with most elements. The formulae of the oxides and hydrides formed by an ELEMENT were treated as one of the basic properties of an element for its classification. He then took 63 CARDS and on each card he wrote down the properties of one element. He selected out the elements with similar properties and pinned the cards together on a wall. He observed that most of the elements got a PLACE in a PeriodicTable and were arranged in the order of their increasing atomic masses. | |
| 1200. |
What is meant by covalent bond ? |
| Answer» Solution :The BOND formed by SHARING equal number of ELECTRONS by participating atoms is called covalent bond. | |