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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.
| 2601. |
The position of eight elements in the Modern Periodic Table is given below where atomic numbers of elements are given in the parenthesis. (i) Write the electronic configuration of Ca. (ii) Predict the number of valence electrons in Rb. i (iii) What is the number of shells in Sr? (iv) Predict whether K is a metal or a non-metal. (v) Which one of these elements has the largest atom in size? (vi) Arrange Be, Ca, Mg and Rb in the increasing order of the size of their respective atoms. |
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Answer» Solution :(i)Electronic configuration of Ca - 2, 8, 8, 2 (ii) Valence electrons in RB is 1. (III) Five (iv) METAL (v) Rb is biggest in size. (VI) Be < Mg < Ca < Rb |
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| 2602. |
The position of eight elements in the modern periodic table is given below where atomic numbers of elements are given in the parenthesis. (i) Write the electronic configuration of Ca. (ii) Predict the number of valence electrons in Rb. (iii) What is the number of shells in Sr ? (iv) Predict whether K is a metal or a non-metal. (v) Which one of these elements has the largest atom in size ? (vi) Arrange Be, Ca, Mg and Rb in the increasing order of the size of their respective atoms. |
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Answer» Solution :(i) Ca = 2,8,8,2 (ii) Valence electrons in Rb = 1 (iii) FIVE (IV) Metal (v) Rb is BIGGEST in SIZE (vi) `BeltMgltCaltRb`. |
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| 2603. |
The poorest conductor among metals is lead,. |
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Answer» |
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| 2605. |
The plastics which soften upon being heated but regains all its original properties on cooling are known as |
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Answer» thermoplastics |
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| 2606. |
The plants bearing round yellow coloured (RrYy) seeds are self pollinated. Represent the result obtained in the F_(2) generation of dihybrid cross with the help of a checker board. Mention the varieties of plants obtained in F_(2) generation. OR What is evolution ? Explain the three evidences for evolution. |
Answer» Solution : OR Evolution is the process of change from simple life forms to complex Life forms by gradual change. It is generating DIVERSITY and SHAPING the diversity. Three factors / evidences and their roles. (i) Analogous organs : The analogous organs have different basic design and structurebut perform similar functions. e.g., The wings of insects and the wings of birds. (ii) Homologous organs : The homologous organs have similar basic design and structure but perform different functions. e.g., Forelimbs of a frog, lizard, bird and man (iii) Fossils: Allow us to make estimates of how FAR back evolutionary relationships GO. Fossils when chronologically arranged help in TRACING the evolutionary history of an organism. e.g., Archaeopteryx looks like a bird but it bears many characters of reptiles. This proves that birds have evolved from reptiles. |
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| 2607. |
The physical state of a substance with lot of empty intermolecular space is |
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Answer» solid |
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| 2608. |
The physical form of calcium carbonate is …. |
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Answer» Limestone |
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| 2609. |
The physical and chemical properties of elements are the periodic function of their atomic numbers - modern periodic law |
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Answer» |
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| 2610. |
What is especially observed when a beam of light is passed through a colloidal solution? |
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Answer» Peltier EFFECT |
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| 2611. |
The pH values of two soft drinks P and Q are 6.4 and 8.2 respectively. If P is acidic, what is the pH value of the alkaline drink? |
| Answer» SOLUTION :PH = 8.2 | |
| 2612. |
The pH values of three acid solutions A, B and C are 1 , 0 and 2 respectively. The order of their acid strength is |
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Answer» `A LT B lt C` |
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| 2613. |
The pH values of solutions marked as A, B, C, D and E are 4, 1, 11, 7 and 9 respectively. (i) Arrange these solutions in the decreasing order of pH. (ii) Arrange these solutions in the increasing order of hydrogen ion concentrations. (iii) In the list of the given solutions identify : (a) Neutral solution (b) Highly alkaline solution ( c) Highly acidic solution (d) Moderately acidic solution (e) Moderately basic solution |
Answer» Solution :(i) Decreasing order of PH values  (ii) Increasing order of `H^(+)` ION concentration : `[H^(+)]=10^(-pH)`  (iii) Identification of SOLUTIONS 
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| 2614. |
The pH values of four solutions A, B, C and D are 5, 12, 8 and 9 respectively. Arrange them in the increasing order of their hydroxyl ion concentration, Which solution among them has strong acidic property? Explain what happens if our mouth contains the pH of solution 'A' |
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Answer» Solution :i) 12 >9>8> 5 or B>D>C>A ii) In solution .A. has strong acidic property. iii) When the PH in the MOUTH is 5(A) TOOTH decay starts. Bacteria present in the mouth produces acid by degradation of sugar and food particles which remain in the mouth after eating. This can lead to tooth decay. Therefore we should brush our teeth with toothpaste because it contain BASE. |
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| 2615. |
The pH value of soil 'A' is 7.5 while that of soil 'B' is 4.5. which of the two soils A or B should be treated with powdered chalk to adjust pH ? Why ? |
| Answer» SOLUTION :Soil .B. is ACIDIC. It should be TREATED with powdered chalk which is BASIC so as to adjust PH. | |
| 2616. |
The pH value of pure water can be increased by |
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Answer» ADDING an acid |
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| 2618. |
The pH of two solutions A and B are 6 and 8 respectively. Now answer the following questions: (i) Which solution has more hydrogen ion concentration? (ii) Which solution is acidic and which one is basic? |
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Answer» Solution :(i) Solution A has more hydrogen IONS than solution B. (ii) Solution A is ACIDIC and solution B is BASIC. |
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| 2619. |
The pH of three solutions A, B, C is 6, 4, 8 receptivity which of the following is the correct option? |
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Answer» `A gt B gt `C DECREASING acidic strength |
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| 2620. |
The pH of the gastric juices released during digestion is |
| Answer» Solution :less than 7 | |
| 2621. |
The pH of stomach fluid is ……….. |
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Answer» 12 |
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| 2622. |
The pH of soil A is 7.5 while that of soil B is 4.5. Which of the two should be treated with powdered chalk to adjust its pH and why ? |
| Answer» SOLUTION :SOIL having pH 4.5 should be TREATED with powdered chalk to adjust its p.H. Soil B is too acidic. Its ACIDITY can be reduced by adding powdered chalk `(CaCO_3)` , which is a base. | |
| 2623. |
The pHof rainwatercontainingdissolvedgaseslikeSO_(3) ,CO_2 ,NO_2will beless than7. |
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Answer» |
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| 2624. |
The pH of pure water is |
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Answer» `1.0` |
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| 2627. |
The pH of lemon juice is |
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Answer» `2.5` |
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| 2629. |
the pHof bloodis from________to _______. |
| Answer» SOLUTION :`7.35,7.45` | |
| 2630. |
The pH of aqueous solution of salt obtained by the reaction between NaOH and CH_(3)COOH is _____ at 25^(@)C |
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| 2631. |
The pHof bakingsodais 9,It isacidinnatural . |
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| 2632. |
The pH of an aqueous solution of sodium hydroxide is |
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Answer» EQUAL to 7 |
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| 2633. |
The pH of an acid solution is |
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Answer» LESS than 7 |
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| 2634. |
The pH of a solution of sodium hydroxide is 9. What will be its pH when this solution is diluted? |
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Answer» LESS than 9 |
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| 2635. |
The pH of a solution is 7.5 . The solution is |
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Answer» ACIDIC . |
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| 2636. |
The pH of a solution is 3.Its [OH^(-)] concentration is…. |
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Answer» `1xx1^(-3)M` It means `[H^(+)]=10^(-3)` `[H^(+)][OH^(-)]=10^(-14)` `[OH^(-)=10^(-14)` `[OH^(-)=10^(-11)]` |
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| 2637. |
The pHof asolution is3.Its[OH^(-)]concentrationis ______. |
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Answer» `1xx10^(-3)M` |
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| 2638. |
The pH of a solution increases when |
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Answer» its `H^(+)` ION concentration increases |
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| 2641. |
The pH of a sample Y is found to be 10. This sample is |
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Answer» SODIUM hydroxide |
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| 2642. |
The pH of a sample of pure water is 7 at room temperature. What will be its pH when a pinch of solid baking soda is dissolved in it?Very near to 7Less than 7More than 7 Exactly 7 |
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Answer» Very NEAR to 7 |
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| 2643. |
The pH of a sample of hydrochloric acid is 3.5. What will be its pH when this solution is diluted? |
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Answer» LESS than 3.5 |
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| 2644. |
The pH of a fruit juice is 5.6 .If you add slaked lime to this juice ,its pH………(increase/decrease) |
| Answer» SOLUTION :INCREASES | |
| 2645. |
The pH of a salt used to make tasty and crispy pakoras is 14. Identify the salt and write a chemical equation for itsformation. List its two uses. |
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Answer» Solution :The salt is baking soda (sodium hydrogencarbonate). `NaCl + H_(2)O + CO_(2) + NH_(3) rarr underset("chloride")underset("Ammonium")(NH_4Cl) + underset("hydrogencarbonate")underset("sodium")(NaHCO_3)` Uses : (1)It is used in soda-ACID fire EXTINGUISHES (2) It is an ingredient of antacids. It neutralises excess acid in the stomach and provides relief. |
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| 2646. |
The pH of a normal healthy human skin is ……….and the pH of the stomach fluid is………. |
| Answer» SOLUTION :7.4,5.5 | |
| 2648. |
Calculate the pH of 10^(-8) M HCl solution . |
| Answer» Solution :The pH of` 1 xx 10^(-8)` M HCl is 6.96 . It is in the RANGE of 6 to 7 . | |
| 2649. |
The pH of 0.001 N sodium hydroxide solution at 25^(@)C is |
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Answer» 3 `POH = 3, pH = 14 - 3 = 11` |
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