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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.
| 5301. |
How much copper can be obtained from 100 g of CuSO_(4) ? |
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| 5302. |
How many vertical columns are there in the Modern Periodic Table? |
| Answer» SOLUTION :In the Modern Periodic Table, there are 18 vertical COLUMNS of ELEMENTS called GROUPS. | |
| 5303. |
How many valence electrons are present in these three elements Li , Na , K ? |
| Answer» Solution :ONE (1) Inference: From this activity, we conclude that in a group, all the elements have same number of valence clectrons. Since valence ELECTRONIC ciclet a p erties of uncernent, the elements in a group have similar CHEMICAL properties. | |
| 5304. |
How many structural isomers can you draw for pentane? |
Answer» SOLUTION :The ISOMERS are as under: 
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| 5305. |
How many structural isomers can you draw for pentane ? |
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Answer» SOLUTION :THREE . `UNDERSET("PENTANE")(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)-underset(H)underset(|)overset(H)overset(|)(C)-H) "" underset("Isopentane")(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)-underset(H)underset(|)overset(H)overset(|)(C)-H)` `underset("Neopentane")(H-underset(H)underset(|)overset(H)overset(|)(C)-underset(H)underset(|)underset(H-C-H)underset(|)overset(H)overset(|)overset(H-C-H)overset(|)(C)-underset(H)underset(|)overset(H)overset(|)(C)-H)` |
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| 5306. |
How many significant figures are there in (i) 3.070 and (ii) 0.0025 ? |
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| 5307. |
How many moles of NaOH must be added to 200 mL of 0.1 M solution of HNO_(3) to get a solution having pH value 2.00 ? |
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Answer» Solution :(i) pH of initial solution (ii) CALCULATION of NORMALITY of the solution after neutralisation (iii) calculation of number of equivalent of `HNO_(3)` NEUTRALISED (iv) calculation of number of MOLES of NaOH required to neutralise this `HNO_(3)` in 200 ml (v) 0.018 |
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| 5308. |
How many moles of Lead (II) chloride will be formed from a reaction between 6.5 g of PbO and 3.2 g of HCl ?[ Atomic mass of Pb = 207 U] |
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| 5309. |
How many moles of HCl are present in 250 "cm"^3 of 0.5M HCl solution. |
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Answer» 1 mole |
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| 5310. |
How many molecules of water of crystallisation are there in (i) Plaster of Paris (ii) washing soda crystals ? |
| Answer» SOLUTION :(i) `1/2` (II) 10. | |
| 5311. |
How many moleculs would be there in 0.01 molesof sodium hydroxide? |
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Answer» `6.023 XX 10^(23)` |
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| 5313. |
How many molecules at present in one gram of hydrogen? |
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Answer» `6.023xx10^(23)` `"2 G of "H_(2)" contains "6.023xx10^(23)` molecules `THEREFORE" 1 g of "H_(2)" will contain"` `(6.023xx10^(23))/(2)xx1` `=3.011xx10^(23)" molecules."` |
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| 5314. |
How manymoleculeare presentin onegramofhydrogen ? |
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Answer» `6.023xx 10^(23)` |
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| 5315. |
How many hydrogen atoms are present in a hydrocarbon with 50 carbon atoms and one triple bond in it ? |
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Answer» 50 |
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| 5316. |
How many horizontal rows are there in the Modem Periodic Table and what are they called ? |
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Answer» SOLUTION :There are SEVEN horizontal ROWS. They are called periods. |
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| 5318. |
How many groups and periods are there in the modern Periodic Table ? How do the atomic size and metallic character of elements vary as we move : (a) down a group and (b) from left to right in a period. |
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Answer» Solution :There are 18 groups and 7 PERIODS in the modern Periodic Table. (a) On moving down a group, the atomic SIZE increases and metallic character also increases. (B) On moving from LEFT to right in a period, the atomic size decreases and the metallic character also decreases. |
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| 5319. |
How many groups and periods are there in the Modern Periodic Table? How do the atomic sizeand metallic character of elements vary as we move:(a) down a group and (b) from left to right in a period |
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Answer» Solution :There are 18 groups and 7 periods in the Modern Periodic Table. (a)• Atomic size increases • METALLIC character increases (b)• Atomic size DECREASES • Metallic character decreases |
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| 5321. |
How many groups and periods are there in the modern periodic table? How do the atomic size and metallic character of elements vary as we move ? (i) down a group and (ii) from left to right in a period. |
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Answer» Solution :There are 18 groups and 7 periods in the modern periodic table. (i) Atomic size GENERALLY INCREASES down a group due to the addition of new shell and metallic character also increases down a group due to the increase in tendency to lose electrons. (ii) Atomic size goes on decreasing along a period from LEFT to right. Metallic character decreases along a period due to decrease in tendency to lose electrons. |
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| 5322. |
How many grams are there in the following? i. 2 moles of hydrogen molecule, H_(2) ii. 3 moles of chlorine molecules, Cl_(2) iii. 5 moles of sulphur molecule, S_(8) iv. 4 moles of phosphorous molecules, P_(4) |
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Answer» Solution :i. 2 moles of hydrogen MOLECULES, `H_(2)`: MASS of 1 mole of hydrogen molecule = 2G `therefore "Mass of 2 moles of hydrogen molecule"=2xx2=4g` ii. 3 moles of chlorine molecule, `Cl_(2):` Mass of 1 moles of chlorine molecule = 71 g `therefore` Mass of 3 mole of chlorine molecules `=71xx3=213g`. iii. 5 moles of sulphur molecule, `S_(8)`: Mass of 1 mole of sulphur molecule = 32g `therefore` Mass of 5 moles of sulphur molecules `=32xx5=160g.` iv. 4 moles of phosphorous molecules, `P_(4)`: Mass of 1 mole of phosphorous molecule = 30.97 g `therefore"Mass of 4 moles of phosphorous molecules "=30.97xx4=123.88g.` |
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| 5323. |
How many grams are there in the following ? (i) 1 mole of chlorine molecule, Cl_(2) (ii) 2 moles of sulphur molecules, S_(8) (iii) 4 moles of ozone molecules, O_(3) (iv) 2 moles of nitrogen molecules, N_(2) |
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Answer» Solution :(i) 1 mole of CHLORINE molecule `Cl_(2)` Atomic MASS of chlorine = 35.5 g `"Mass of 1 mole of chlorine"="Atomic mass"xx"ATOMICITY"` `=35.5xx2=71g` (ii) 2 moles of sulphur molecules `S_(8)` Atomic mass of `S_(8)=8xx32=256g` `"Mass of 2 moles of "S_(8)="Atomic mass "xx"Number of moles"` `=256xx2=512g` (III) `"4 moles of OZONE molecules "O_(3)` `"Atomic mass of "O_(3)=3xx16=48g` (iv) `"2 moles of Nitrogen molecules "N_(2)` `"Atomic mass of "N_(2)=2xx14=28g` `"Mass of 2 moles of Nitrogen"=28xx2=56g` |
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| 5324. |
How many grams are there in : (i) 5 moles of water (ii) 2 moles of Ammonia (iii) 2 moles of Glucose |
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Answer» Solution :(i) 5 moles of water `"Mass of 1 mole of water "(H_(2)O)=18G(2+16)` `therefore"Mass of 5 moles of "H_(2)O=18xx5=90g`. (II) 2 moles of ammonia. Mass of 1 mole of ammonia `(NH_(3))=17G (14+3)` `therefore"Mass of 2 moles of ammonia "=17xx2=34g`. (iii) 2 moles of glucose. `"Mass of 1 mole of glucose "(C_(6)H_(12)O_(6))=180g (72+12+96)` `therefore"Mass of 2 moles of glucose "=180xx2=360g.` |
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| 5325. |
How many elements were known when Mendeleev started the classification of elements ? |
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| 5329. |
How many electrons are present in the outermost shell of fluorine ? |
| Answer» SOLUTION :7 ELECTRONS | |
| 5330. |
How many covalent bonds are present in a milecule with the chemical formula C_(6)H_(6) ? |
Answer» SOLUTION : NUMBER of COVALENT BONDS = 15. |
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| 5331. |
How many carbon atom/s are present in formic acid ? |
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Answer» 1 |
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| 5332. |
How many atoms are present in 5 moles of oxygen? |
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Answer» Solution :ONE mole of oxygen contains `6.023xx10^(23)" atoms"` `therefore" 5 MOLES of oxygen contain"=5xx6.023xx10^(23)` `=30.115xx10^(23)` `=3.0115xx10^(24)" atoms"` |
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| 5333. |
How many atoms and moleculesare present in124 gm of phosphorus(P4) |
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| 5335. |
How is 'X' obtained ? Give chemical equation. |
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Answer» Solution :.X. i.e., calcium HYDROXIDE is obtained by ADDING water to quick LIME `(CaO)` as per the FOLLOWING equation : `CaO(s)+H_(2)O(l)toCa(OH)_(2)(aq)` |
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| 5336. |
How is the structural formula of any hydrocarbon compound represented ? Explain it with an example of ethane. |
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Answer» Solution :The structural formula of SIMPLE carbon compound is written in two steps as follows : STEP 1 : In step 1, carbon atoms are linked TOGETHER with a single bond. Step 2 : In step 2 : In step 2, the remaining valencies of carbon are satisfied with hydrogen atoms. Three valencies of each carbon atom remain unsatisfied, so each carbon is BONDED to other three hydrogen atoms giving following structure of ethane : `H-underset(H)underset(|)overset(H)overset(|)C-underset(H)underset(|)overset(H)overset(|)C-H` |
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| 5337. |
How is the reaction Fe + CuSO_(4) to FeSO_(4) + Cu a redox reaction ? |
| Answer» Solution :In the reaction , Fe LOSES two ELECTRONS and GETS oxidized to ` Fe_(2+)` ion. `Cu^(2+)` ion, on the other hand, receives these two electrons and gets REDUCED to Cu. Hence , this is a redox reaction . | |
| 5338. |
How is the product formed during the chemical reaction ? |
| Answer» Solution :In a chemical reaction, bonds present in the MOLECULES of REACTANTS are broken and new bonds are formed between different atoms in the products. This RESULTS in the conversion of reactants into product. | |
| 5339. |
How is the problem regarding the position of cobalt (""^59Co) and nickel (""^59Ni) in Mendeleev's periodic table resolved in Modern Periodic table? |
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Answer» Solution :(i) ACCORDING to Mendeleev.s periodic law, ELEMENTS are arranged in the order of their increasing ATOMIC masses. (ii) When Co. and Ni were put in the group on the basis of their chemical properties it was found that Co having HIGHER mass of 58.9 comes first and Nickel with slightly lower atomic mass of 58.7 comes later. (III) Modem Periodic table resolved this problem. According to the Modem Periodic law, elementsare arranged in their increasing order of atomicnumber. (iv) The atomic number of Cobalt is 27 comes first andNickel with atomic number 28 comes next even if their atomic masses are in the reverse order. |
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| 5340. |
How is the painful effect of a honeybee sting treated ? |
| Answer» Solution :HONEYBEE injects an ACID. So, a MILD base LIKE BAKING soda is used. | |
| 5341. |
How is the method of extraction of metals high up in the reactivity series different from that metals in the middle ? Why the same process cannot be applied for them ? Explain giving equations, the extractions of sodium. |
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Answer» Solution :Metals high up in reactivity series are EXTRACTED by electrolytic reduction. While those in the middle are extracted first by CONVERTING into oxide and then reducing by carbon. Same process cannot be applied as METAL at the TOP are more reactive to oxygen then metal in the middle and metals in the middle are present in sulphide and carbonate ores. Molten sodium chloride is taken for electrolytic reduction. The metals are deposited at the cathode and chlorine is liberated at anode. At cathode : `Na^(+) + e^(-) rarr Na` At anode : `2Cl^(-) rarr Cl_(2) + 2e^(-)` |
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| 5342. |
How is the increase in demand for energy affecting our environment adversely? |
| Answer» SOLUTION :The INCREASE in demand for energy affects our ENVIRONMENT adversely DUE to the increase POLLUTANTS like `CO_(2), CO, SO_(4)` etc. are released into the atmophere which lead to greenhouse affect. | |
| 5343. |
How is the evolution of gas indicated in a chemical equation ? |
| Answer» Solution :The GAS EVOLVED is INDICATED by an ARROW DIRECTED upwards at the end of the formula of the gas. | |
| 5344. |
How is the end product of nutrition glucose breaks down among all the organisms under the conditions given below. i) In the presence of atmospheric oxygen. ii) In the absence of atmospheric oxygen iii) in muscle cells due to lack of oxygen |
| Answer» Solution : i) Carbon dioxide + water + ENERGY II) Ethanol + carbon dioxide + energy iii) LACTIC ACID + energy | |
| 5345. |
How is the concentration of hydroxide ions (OH^(-)) affected when excess base is dissolved in a solution of sodium hydroxide ? |
| Answer» SOLUTION :Excess BASE dissolved in a solution of SODIUM hydroxide will release more hydroxide ions. Therefore, concentration of hydroxide ions `(OH^-)` will increase | |
| 5346. |
How is the concentration of hydroxide ions (OH^(-)) affected ,when excess base is dissolved in a solution of sodium hydroxide ? |
| Answer» Solution :On DISSOLVING base in a solution of SODIUMHYDROXIDE, concentration of `OH^(-)` IONS per unit volume in the solution INCREASE. | |
| 5347. |
How is the concentration of hydroxide ions [OH^(-)] affected when excess base is dissolved in a solution of sodium hydroxide ? |
| Answer» Solution :When excess of base is DISSOLVED in a solution of SODIUM HYDROXIDE, concentration of `OH^(-)`IONS increases. | |
| 5348. |
How is the concentration of hydroxide ions (OH -) affected when excess base is dissolved in a solution of sodium hydroxide ? |
| Answer» Solution :The cocentrations of HYDROXIDE ions `(OH^(-))`would INCREASE when excess BASE is dissolved in a solutions of sodium hydroxide. | |
| 5349. |
How is the concentration of hydronium ions (H_3O^+) affected when a solution of an acid is diluted ? |
| Answer» SOLUTION :CONCENTRATION of HYDRONIUM ions is decreased when the solution of an acid is DILUTED. | |
| 5350. |
How is the concentration of hydronium ions (H_3O^(+)) affected when a solution of an acid is diluted ? |
| Answer» SOLUTION :The concentration of hydronium IONS decreases when a solution of an acid is DILUTED. | |