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.
| 1901. |
Which of the following statements about the Modern Periodic Table is correct? |
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Answer» It BAS 18 HORIZONTAL rows known as Periods |
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| 1902. |
Turmeric spots on kitchen cloth turn brown-red when washed with soap. Why? |
| Answer» Solution :Because SOAP contains ALKALI which COMBINES with TURMERIC. | |
| 1903. |
You are given two colourless solutions present in two test tubes. One out of these is ethyl alcohol and the other is acetic acid. Give three tests to identify these. |
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Answer» Solution :Smell. The tube in which the liquid has a vinegar like or fruity smell is acetic acid while the other with a very little pungent smell is ethyl alcohol. Litmus Test. Add a strip of blue litmus SEPARATELY in both the tubes. The tube which turns blue litmus red contains acetic acid while the other which does not change its COLOUR is that of ethyl alcohol. SODIUM hydrogen carbonate test. Add a small amount of SOLID sodium hydrogen carbonate `(NaHCO_(3))` in both these tubes. The one which gives a brisk effervescence contains acetic acid while the other in which no effervescence is NOTICED contains ethyl alcohol. |
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| 1905. |
What is meant by electrolysis ? Mention its two uses with examples. |
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Answer» SOLUTION :When electric current is passed through an aqueous solution or molten ionic compound, the ions of the compound form products on electrodes by electrolytic oxidation - reduction. This process is called an ELECTROLYSIS. Uses :(1) Gas and metal can be obtained from an aqueous solution of salt. For example, Electrolysis of an aqueous solution of NaCl produces Na metal and `Cl_(2)` gas. (2) The coating (protective LAYER) of ONE metal can be formed on the surface of another metal. For example, Gold plating can be carried out on the surface of silver articles. Zn layer can be formed on the surface of iron. |
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| 1906. |
Write the skeletal equation for the following reactions: (i)Hydrogen sulphide reacts with sulphur dioxide to from sulphur and water. (ii) Methana on burning combines with oxygen toproduce carbon dioxide and water . What is the need of balance equations ? |
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Answer» Solution :(i) `4H_(2)S+2SO_(2)rarr6S+4H_(2)O` (ii) `CH_(4)+2O_(2)rarrCO_(2)+2HO` To obey the law of CONSERVATION of mass, so that the NUMBER of atoms of each element before and afterthe reaction remain the same. |
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| 1907. |
What would be the electron dot structure of a molecule of sulphur which is made up of eight atoms of Silnhur ? |
Answer» SOLUTION :
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| 1908. |
Write the names given to the vertical columns and horizontal rows in the Modern Periodic Table. How does the metallic charcter of elements very on moving down a vertical column ? How does the size of atomic radius vary on moving left to right in a horizontal row ? Give reason in pupport of your answer in the above two cases. |
| Answer» SOLUTION :Vertical columns are KNOWN as Groups while horizontal rows are called Periods in the Modern Periodic Table. Metallic CHARACTER of the ELEMENTS increases down the GROUP whereas atomicsize or atomic radius decreases along a period. For details, consult section 5.5. | |
| 1909. |
Which of the following respesents a precipitation reaction? |
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Answer» `A_((s))+B_((S))toC_((s))+D_((s))` |
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| 1910. |
Why should curd and sour substances not be kept in brass and copper vessels ? |
| Answer» SOLUTION :Curd and other sour substance CONTAINS acids Thereforewhen they are KEPT in brass and copper vessel , the METAL reacts with the ACID to liberate hydrogen gas which are harmfull product ,thereby spolling the food . | |
| 1911. |
The rocky impurity associated with the ore is called flux . |
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Answer» |
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| 1912. |
What type of oxides are formed when non-metal combine with oxygen ? |
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Answer» Solution :As they form TWO TYPES of oxides : (a) Neutral oxides such as CO, NO, etc. (b) ACIDIC oxides such as `SO_(2),CO_(2)`, etc. |
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| 1913. |
What is electroplating? |
| Answer» Solution : Electroplating is a METHOD of coating one metal aver another metal by PASSING ELECTRIC CURRENT | |
| 1914. |
When a copperplate is dipped into a solution of ferrous sulphate , the colour of the solutionwill change to |
| Answer» ANSWER :D | |
| 1915. |
What are hygroscopic substance |
| Answer» Solution :Certain substances, when exposed to the ATMOSPHERIC air at ordinary TEMPERATURE, absorb moisture WITHOUT changing their physical STATE. Such substances are called hygroscopic substances and this property is called hygroscopy. | |
| 1916. |
Which one of the following is most electronegative?FClBrI |
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Answer» F |
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| 1917. |
What is meant by ternary solution? |
| Answer» Solution :SOLUTIONS which contain three components are called ternary solutions. E.g. If SALT and sugar are added to WATER, both dissolve in water forming a solution. Here two solutes are dissolved in ONE solvent. Therefore it is ternary solution. | |
| 1918. |
When a little sulphur in a spoon is heated,it burns with a blue flame which slowly disappears after some time and we can feel a pungent odour. This pungent odour is due to |
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Answer» CARBON dioxide |
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| 1919. |
The total number of atoms represented by the compound CuSO_(4).5H_(2)O is ……………….. . |
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Answer» 27 |
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| 1920. |
Which one of the following metals is most reactive and stored in kerosene? |
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Answer» Iron |
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| 1921. |
When a few drops of phenolphthalein are added to a dilute solution of sodium hydroxide, a pink colour is produced. What will be the colour of the final mixture when excess of HCI is added to it ? (jusify your answer) Arrange the metals iron, magnesium, zinc and copper in the increasing order of their reactivity. What will be the two observations made by the student when iron filings are added to copper sulphate solution ? |
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Answer» SOLUTION :Phenolphthalein acquires pink colour in SODIUM hydroxide solution because of its basic NATURE. On adding excess of HCl, the solution will become acidic and the solution will change colour from pink to colourless. Or The increasing order of the reactivity of metals is : `CultFeltZnltMg.` The displacement reaction taking place in aqueous solution is : `Fe(s)+underset("(Blue)")(CuSO_(4)(aq))rarrunderset("(Light green)")(FeSO_(4)(aq))+underset("(Brown)")(Cu(s))` The observations made from the EXPERIMENT are : (i) Colour of the solution will change from blue to light green. (II) Brown deposit will be formed at the bottom of the tube. |
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| 1922. |
Which of the following statements is correct regarding the particles of a solute that get dissolved in a solvent ? |
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Answer» They can be separated by filtration |
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| 1923. |
What does energy flow diagram indicate ? |
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Answer» Solution :Energy flow diagram indicates the following: a)Energy flow is undirectional B)As much is wasted only a limited number of TROPHIC LEVELS (3 or 4) are found in the food chain. c) Biological magnification of harmful non-biodegradable SUBSTANCE OCCUR in food chain. |
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| 1924. |
Which of the following compounds will react with hydrochloric acid to form salt and water ? |
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Answer» `Na_(2)SO_(4)` |
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| 1925. |
The valency of mercurous ion is |
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Answer» two |
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| 1926. |
The solution in which water acts as a solvent, it is called non-aqueous solution. |
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Answer» |
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| 1927. |
Which of the following solution is the most basic. |
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Answer» PH= 8.2 |
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| 1928. |
Write the chemical name and formula of common salt. List two main sources of common salt in nature. Write any three uses of common slat. How is it connected to our freedom struggle ? |
| Answer» SOLUTION :For ANSWER, CONSULT SECTION `2.11.` | |
| 1929. |
What problem does arise when hard water is treated with soap ? |
| Answer» Solution :HARD WATER does not PRODUCE lather with soap EASILY. | |
| 1930. |
What is observed when a solution of potassium iodide is added to a solution of lead nitrate ? Name the type of reaction. Write a balanced chemical equation to represent the above chemical reaction. |
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Answer» Solution :Yellow precipitate of lead OXIDE is formed. The reaction is precipitation reaction. `Pb(NO_(3))(aq)+2Kl(aq)toPbl_(2)+2KNO_(3)(aq)`. This reaction is ALSO called double DISPLACEMENT reaction. |
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| 1931. |
Which of the following element is most electropositive ? |
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Answer» H |
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| 1932. |
Write the name of CH_3 -CH_2 - CH_3 . |
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Answer» SOLUTION : IUPAC parts of the complete name of the structural formula: Root word, Primary suffix, Secondary suffix, Prefix. (i) There are 3 C atoms in the chain. Therefore, root word = prop. (ii) Only C-C covalent bonds are present in the chain. Therefore, primary suffix is ANE. (iii) There is no FUNCTIONAL group and SUBSTITUENT with the parent chain. Therefore, secondary suffix and prefix are not involved. Thus the IUPAC name of the given compound is derived as: Root word + Primary suffix Prop + ane = Propane |
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| 1933. |
Write the IUPAC name of the compound CH_3 - CH_2 - undersetoverset(|)(COOH)(C)H - CH_3 |
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Answer» Solution :(a) There are 4 C atoms in the chain involving -COOH GROUP, therefore, the root word is .but.. (b) Only C-C bonds appear between C atoms in the chain, therefore, primary SUFFIX is! .ane.. Thus, Base name = root word + primary suffix = but + ane = butane (c) There is -COOH group in the chain, therefore, secondary suffix is .oic acid.. (d) There is one methyl radical `(-CH_3)` at CARBON 2 of the chain, therefore, the prefix is .2-methyl.. Thus, the IUPAC name of the given compound is derived as: Prefix + Base name -e + Secondary suffix 2-Methyl + butane - e + oic acid = 2-Methylbutanoic acid |
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| 1934. |
Which metals will melt, if you keep them on your palm ? |
| Answer» SOLUTION :GALLIUM (GA) and CAESIUM (CS). | |
| 1937. |
When you add sodium hydrogen carbonate to acetic acid in a test tube, a gas liberates immediately with brisk effervescence. Name this gas. Describe the method of testing this gas. |
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Answer» Solution :The gas is `CO_(2)` When the gas is passed through LIME WATER, it turns lime water MILKY. |
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| 1938. |
Which amongst the following is most non - metallic ? |
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Answer» nitrogen |
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| 1939. |
Which of the following compound is an ionic compound ? |
| Answer» Answer :C | |
| 1940. |
Which of the following is (are) straight - chain hydrocarbon(s) ? |
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Answer» ` CH_(3) -CH_(2) -CH_(2)-CH_(3)` |
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| 1941. |
When a chemical bond between two atom is formed, the potential energy of the system |
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Answer» DECREASES |
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| 1943. |
Which metals react with cold water ? |
| Answer» Solution : SODIUM, POTASSIUM and CALCIUM REACT with COLD water. | |
| 1944. |
Write the molecular formula of (i) methane and (ii) ethanol. |
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Answer» SOLUTION :Methane : `CH_(4)` `Ethanol : `C_(2)H_(5)OH` |
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| 1945. |
Which of the following statement is incorrect when Calcium oxide reacts vigorously with water? |
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Answer» SLAKED LIME is formed |
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| 1946. |
What are the different methods of contraception? |
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Answer» Solution :Contraceptive method can be bordly divided into the following types : Natural method : It involves avoiding the chances of meeting of sperms and ovum. In this method, the sexual act is avoided from 10th to 17th of the menstrual cycle because during this epriod, ovulation is expected and therefore the chance of fertilization are very high. * Barrier method : In this method, the fertilization of ovum and sperms is prevented with the help of barriers. Barriers are available for both males and females. Condoms are barriers made of thin rubber that are used to cover penis in male and vagina in females. * Oral contraceptives : In this method tablets or drugs are taken orally. They contain small doses of harmones that prevent the release of eggs and thus fertilization cannot occur. * Implants and surgical METHODS : Contraceptive DEVICES such as the loop or copper - T are placed in uterus to prevent PREGNANCY. Some surgical methods can ALSO be used to block the gamete transfer to prevent the transfer of sperms known as vastectomy. Similarly, fallopian tubes of the female can be blocked so that egg will not reach the uterus known as TUBECTOMY. |
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| 1947. |
Write general outer electronic configuration of 4f series elements. |
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Answer» |
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| 1948. |
Which amongthe followingfactorsaffecttherateof areaction? |
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Answer» Surfaceareaof REACTANTS |
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| 1949. |
What is hard soap? |
| Answer» Solution :Soap, which are prepared by the saponification of oils or fats with CAUSTIC soda (sodium hydroxide), are KNOWN as hard soaps. They are USUALLY USED for washing purposes. | |
| 1950. |
Write four uses of ethyl alcohol. |
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Answer» Solution :(i) It is USED in the manufacture of paints, MEDICINES, DYES, soaps, etc. (ii) It is used in the preparation of organic COMPOUNDS like ether, chloroform and iodoform. (iii) It is used as a fuel in internal combustion engines. (iv) It is used in low temperature thermometers. |
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