This section includes 7 InterviewSolutions, each offering curated multiple-choice questions to sharpen your Current Affairs knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
Can fuels be made in the laboratory? Explain |
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Answer» No fuels can't be OBTAIN in LABORATORY or something as it REQUIRES lot of heaat , temperature and PRESSURE since they are obtained from ancient plants so it requires time..........lot of time |
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| 2. |
Class XII problemHow can you distinguish between benzylchloride and p- chloro toluene? |
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Answer» Benzyl chloride is an ALIPHATIC chloride, UNLIKE p-chlorotoluene which is an aromatic chloride. So benzyl chloride will give AgNO3 TEST (FORM white ppt.) while p-chlorotoluene will not give AgNO3 test. |
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| 3. |
Class XII problemDifferentiation of Ethanol and Phenol |
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Answer» Phenol turns blue LITMUS RED DUE to its slightly BASIC nature. Ethanol fails to do so. |
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| 4. |
Class XII problemIodoform is obtained by the reaction of acetone with hypoiodite not with iodine.why? |
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Answer» Beacause hypoiodite SOLUTION is act as base u can use iodine but you have to ADD base while using iodine. |
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| 5. |
Class XII problemHighest oxidation state in d-block elements |
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Answer» Highest oxidation state is +9 and of Ir (IRIDIUM). atomic NUMBER 77 |
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| 6. |
Class XII problemWhich metal is purified by vapour phase refining? |
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Answer» Nickel (MOND's process) and Zirconium and TITANIUM (Van Arkel method) are purified by vapour PHASE REFINING. |
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| 7. |
Class XII problemPolyacrylates and polyesters |
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Answer» Polyester is a polymer which contains the ester functional group. whereas polyacrylate is a polymer of acrylate. |
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| 8. |
Class XII problemWhat to study in Coordination Compound ?? |
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Answer» TRENDS in ionisation enthalpy, Variation in oxidation states (memorize the stable oxidation states of first row d block elements), PREPARATION and reactions of potassium permanganate and potassium dichromate, lanthanoid contraction, difference between lanthanoids and actinoids INCLUDING general ELECTRONIC CONFIGURATION. |
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| 9. |
Class XII problemwhy p-dichlorobenzene has higher boiling point & lower solubility than ortho & meta dichlorobenzene? |
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Answer» P-dichlorobenzene SHOWS intermolecular hydrogen BONDING DUE to which its molecules are strongly attracted to each other. Thus its boiling point increases. It has lower SOLUBILITY because to be soluble it has to break its hydrogen bonds and form NEW hydrogen bonds with water which is not feasible. |
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| 10. |
Class XII problemHow many ions are produced from the complex CO(NH3)6Cl2 when dissolved in liquid? |
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Answer» 3 IONS. 2 Cl- ions, and one [Co(NH3)6]2- ion. Note that [Co(NH3)6]2- will not DISSOCIATE into 7 ions one Co and 6 NH3 as there is coordinate bond instead of ionic bond between them. |
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| 11. |
Class XII problemdistinguish test between CH3CHO and C6H5CH2CHO |
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Answer» Iodoform test |
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| 12. |
Class XII problemFARADAYS LAW OF ELECTROLYSIS |
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Answer» 1ST law - The mass of a SUBSTANCE deposited or LIBERATED at electrode during electrolysis is directly proportional to quantity of electricity passed through it. w = ZIt 2 nd law - When same quantity of electricity is passed through DIFFERENT electrolytes connected in series, then mass of the substance deposited or liberated at the electrode is directly proportional to its chemical equivalent. w1/w2 = E1/E2 |
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| 13. |
Class XII problemChloroform in open air |
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Answer» Chloroform reacts with the OXYGEN in air to GIVE a poisonous GAS phosgene. |
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| 14. |
Class XII problemwhat r the important topics in p block?? |
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Answer» Ideally, you should STUDY all the examples, intext questions and exercise questions (about 100), but if you are short of time, you should atleast study PROPERTIES of hydrides of Group 15, difference between white ans red phosphorus, reaction of white phosphorus and Naoh, Reaction of PCl3 and PCl5 with water, Oxoacids of phosphorus and sulphur, Bleaching action of SO2 and Cl2, Anomalous properties of FLUORINE, PREPARATION and few other REACTIONS of Xenon compounds. |
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| 15. |
What is the composition of port land cement |
| Answer» Composition. Portland cement consists essentially of compounds of lime (CALCIUM OXIDE, CaO) mixed with silica (SILICON dioxide, SiO 2) and alumina (aluminum oxide, Al 2O 3). The lime is OBTAINED from a calcareous (lime-containing) raw material, and the other oxides are derived from an ARGILLACEOUS (clayey) material. | |
| 16. |
Class XII problemConductivity and molar conductivity |
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Answer» Conductivity |
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| 17. |
About bhors and rutherford models of an atom |
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Answer» Bohr's model: In 1913 Bohr proposed his quantized shell model of the atom to EXPLAIN how ELECTRONS can have stable orbits around the NUCLEUS. The motion of the electrons in the Rutherford model was unstable because, according to classical mechanics and electromagnetic theory, any charged particle moving on a curved path emits electromagnetic radiation; thus, the electrons would lose ENERGY and spiral into the nucleus. To remedy the stability problem, Bohr modified the Rutherford model by requiring that the electrons move in orbits of fixed size and energy. The energy of an electron depends on the size of the orbit and is lower for smaller orbits. Radiation can occur only when the electron jumps from one orbit to another. The atom will be completely stable in the state with the smallest orbit, since there is no orbit of lower energy into which the electron can jump. Rutherford model: By 1911 the components of the atom had been DISCOVERED. The atom consisted of subatomic particles called protons and electrons. However, it was not clear how these protons and electrons were arranged within the atom. J.J. Thomson suggested the"plum pudding" model. In this model the electrons and protons are uniformly mixed throughout the atom: |
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| 18. |
Colour of pottasium permanganatebromineand copper sulphate i want their formulas also |
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Answer» POTASSIUM BROMINE FORMULA = (KBR) COLOR = REDDISH BROWN POTASSIUM PERMANGNET FORMULA = KMNO4 COLOR = PURPLE COPPER SULPHATE CUSO4 COLOR = BLUE |
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| 19. |
ask a friend to light an incense stick standing in a corner of room u stand in the other corner does the smell from burning incense stick reach someone at the other end at same time |
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Answer» The smell does not reach at the same time because smell is transferred by DIFFUSION of GASES which is fast but not INSTANTANEOUS. |
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| 20. |
Sponge can be compressed is it a solid why? why dont you be able to compress a wooden block |
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Answer» Even though SPONGE is a solid, there exist holes in the sponge in which AIR is PRESENT. When sponge is compressed, this air is expelled. The PARTICLES of sponge are compressed to a very small extent. |
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| 21. |
Take some finely powdered salt not crystals and keep it in 2 different jars .which shape does the powdered salt take?can you say salt as a liquid based on its change in shape? |
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Answer» The powdered salt particles take the SHAPE of the jar. |
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| 22. |
Let us strech a rubber band is there any change its shape is it solid or liquid why? |
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Answer» Solids usually don't change shape. But rubber band being a solid changes shape only when external force is APPLIED on it. But in the ABSENCE of force it retains to its original position. And so rubber band is a solid. It is similar to a balloon which BULGES in case of external force applied and then retains it original shape when external force is removed. |
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| 23. |
Among HCL and NH₃ how to know which gas travelled fast |
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Answer» Rate at which GASES travel are inversely proportional to their molecular mass, |
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| 24. |
Why do we wrap a blanket around a person whose clothes have caught fire? |
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Answer» All together for a fire to consume, each of the three components of the fire triangle must be available: heat, fuel, and oxygen. |
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| 25. |
Substances which can be found in three states like water |
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Answer» Carbon dioxide EXISTS as a SOLID below -78 degrees CELSIUS, as a liquid below -57 degrees celsius, as a gas above -57 degrees celsius. |
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| 26. |
Name the organic solvent that can dissolve HCl gas? |
| Answer» HCL gas soluble in ETHANOL, METHANOL, ethaer and ALSO in water. | |
| 27. |
Why are zinc ores and sulphide ores concentrated by froath flotation? |
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Answer» The principle of froth FLOATATION is the preferential wetting (dissolving) of ore and gangue particles by water and pine OIL. The ore is preferentially WETTED by pine oil and the gangue is wetted by water. They can then be SEPARATED as the ore with the pine oil rises to the SURFACE. |
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| 28. |
How to know whuch gas travelled fast in a test tube |
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Answer» The gas having the SMALLEST MOLAR MASS will travel the fastest. (Graham's LAW) |
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| 29. |
What is the aberivation of ddt |
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Answer» DDT-Dichlorodipheyltrichloroethane |
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| 30. |
Chapter Redox reaction ......please see the attachment for question |
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Answer» 2MnO4+5 C2O4+16 H |
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| 31. |
What is E.C of POTESUM |
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Answer» Do you want to know the electronic configuration of potassium ? |
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| 32. |
1Why does the bond angle in water is 104 31` basing on VSEPRT? |
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Answer» In water, the central atom, oxygen has two bond pairs and two lone pairs. Thus, it should have a bent shape (please comment if you have any doubts REGARDING this). The bond ANGLE should be 109.5 degrees, but the bond angle decreases DUE to REPULSION between lone pairs and bond pair-lone pair repulsion. |
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| 33. |
Why toothpaste are basic in nature |
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Answer» A toothpaste contains some fluoride, some calcium CARBONATE, some water and some flavour related CHEMICALS. Some hydroxide of aluminum of other other METALS is present. Some TIMES small amounts of detergents are ADDED. These are basic in nature. |
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| 34. |
What is the significance of bionomial nomenclature? |
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Answer» It is the METHOD of NAMING particular ORGANISM by a standard name known all over the WORLD |
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| 35. |
What are the disadvantage of periodic table |
| Answer» HYDROGEN resemble both alkali metals and halogens but it has been PLACED with alkalis.the lanthanides and acitinides have not been placed in the main body of the table.place of element is no sure in the modern PERIODIC table.some similar elements are separated,while some dissimilar elements have been placed in th group.presence of some anomalous pairs of elements.the ISOTOPES of an element have no place in the periodic table. | |
| 36. |
List 2 gases on burning carbon? Pls tell me itz urgent |
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Answer» CARBON MONOXIDE and carbon DIOXIDE |
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| 37. |
Give the defination of acid with some three examples |
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Answer» ACID IS A SOLUTION WHICH IS SOUR TO TASTE , RELEASE HYDROXYL IONS AND TURNS LITUMS PAPER RED EXAMPLE;SULPHURIC ACID,NITRIC ACID,HYDROCHLORIC ACID ETC |
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| 38. |
What is H2So4 ? and where it is used? |
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Answer» H2SO4 is the molecular formula for Sulfuric acid. It is USED in the PRODUCTION of many fertilizers and chemicals. It is also used in the manufacturing of BATTERIES,dyes and MEDICINES. |
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| 39. |
What mass of oxygen gas would be required to react with 3 g of hydrogen gas? |
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Answer» Hydrogen and OXYGEN combine in the ratio of 1:8 means that 1.0g of hydrogen GAS requires 8g of oxygen gas.to FORM WATER. |
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| 40. |
What is chemical change and physical change ? |
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Answer» The CHANGE which is PERMANENT is CHEMICAL change.The change which is TEMPORARY is PHYSICAL change. |
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| 41. |
Having seen formula of any compound can we identity that it has ionic or covalent bond? |
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Answer» From the formula of the compound it may not be possible to KNOW that the bond present in a compound is ionic or covalent. |
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| 42. |
How will you convert benzamide into aniline |
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Answer» 1) aniline -> benzamide diazotize the aniline and trap out with CO2 to form benzonic acid, then make an amide. probably easiest way is to make the acid chloride with (COCI)2 and then TREAT with NH3. |
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| 43. |
Does hydrogen has the lowest ignition temperature |
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Answer» No. Hydrogen does not have the lowest ignition temperature. There are natural GAS and many other fuels and materials which ignite at much LESS temperatures. |
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| 45. |
Hello,can anyone solve this matching ?I herewith enclose attachment regarding chemistry doubt in ( 17 th question ) matching. Please explain briefly. |
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Answer» OPTION Goes With (a) S-tras (b) S- CIS (c) tras (d) cis These are the structures NAMES , the only way is to memorise them. (please TELL me if my answers are wrong)... Thanks.. |
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| 46. |
Reaction o fchlorine with hot and concentrated NaOH?" |
| Answer» 2 NAOH + 2 Cl = NaCl + NaClO( SODIUM HYPOCHLORITE) + H₂O | |
| 47. |
What isthe effect of synergic bonding interaction in a metal carbonyl complex? |
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Answer» It increases the strength of the BOND between the METAL and the CO GROUP. |
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| 48. |
How many valence electrons does pottasium have?explain. |
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Answer» Atomic no. of potassium (K) is 19. |
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| 49. |
What is the electronic configuration of potassium? |
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Answer» The ATOMIC no.of k=19 |
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