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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. |
write the balanced chemical equation for the reaction between lead metal and copper chloride solution what type of a reaction is this? |
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Answer» 2Pb +CUCL2 -> 2PbCl + Cu hope this is the answer....... |
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| 2. |
In which subshell does the electronicconfiguration of lanthanoids ends ? |
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Answer» Lanthanides have the general electron CONFIGURATION of the type (XE)4f N 6s2. They're called 4f elements as they have incompletely filled 4f subshells. Hope this HELPS ✌ |
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| 3. |
if the wavelength of the first line of balmer series of the hydrogen atom is 656.1nm, the wavelength of the second line of this series will be |
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Answer» If the wavelength of the FIRST line of the Balmer SERIES of HYDROGEN ATOM is 656.1 nm the wavelngth of the second line of this series would be. λ=5×656.1×163×36=486.0nm |
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| 4. |
Calculate the no. of molecule & oxygen atoms present in O^9 gram of water |
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Answer» Answer: How many MOLECULES of water and OXYGEN atoms are present in 0.9g of water? Atomic Mass of H = 1 a.m.u Atomic Mass of O = 16 a.m.u Therefore Relative Molecular Mass of Water ( H2O ) is 1(2) + 16(1) = 2 + 16 = 18 Therefore, 1 mole of Water contains 18 G of Water. 0.9 g of Water hence contains 0.05 moles of Water. Avogadro's Number = 6.023×1023 Hence, 1 mole of Water contains 6.023×1023 molecules of Water. Therefore, 0.05 moles contains 0.05×6.023×1023 molecules which is 3.0115×1022 molecules. For the SECOND part of your question, the number of water molecules equals the number of atoms of oxygen since each water molecule contains only 1 oxygen atom. Therefore, the number of oxygen atoms is same which is 3.0115×1022 Explanation: PLEASE mark as brainliest answer and follow me please and thank me please Because I am a very good boy |
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| 5. |
How many moles of sodium chloride present in 250 ml of 0.50 ml of nacl solution |
Answer» Moles of sodium CHLORIDE PRESENT is 0.125 moles.follow me please... MARK as BRAINLIEST please... |
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| 6. |
The process during which a solid changes into its liquid state at a fixed temperature on heating is called?Pls answer this |
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Answer» Answer:The process during which a SOLID CHANGES into its liquid state at a FIXED temperature on heating is called melting of fusion. Explanation:hope tbis will help U please mark me as a brainliest |
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| 8. |
1. Which of the following can be used to testthe acidic nature of ethanol? (KCET-2019)1) Blue litmus2) Na CO3) NaHCO4) Na metal |
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Answer» Answer: |
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| 9. |
A definite mass of gas taken in a cylinderof volume 1L . when it is transffered tocylinder of volume 2L , what will be thenew volume of gas ? |
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Answer» Answer: 2 L Explanation: THE NEW VOLUME WILL BE 2 L SINCE GASES HAVE NO DEFINITE SHAPE OR VOLUME THEY ACQUIRE SHAPE AND VOLUME OF THE CONTAINER WHICH THEY ARE TAKEN. |
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| 10. |
What is mean by oxidation of elements |
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Answer» Answer: OXIDATION of elements MEANS moving of electrons. suppose if IRON reacts with oxygen then iron loses some electrons and oxygen GAINS those electrons. |
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| 11. |
What is the oxidation state of Cu inCuCl2 ? |
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Answer» Oxidation state of : Cu = +2 Cl = -1
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| 12. |
Which of the following can be used to testthe acidic nature of ethanol? (KCET-2019) |
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Answer» Answer: LITMUS paper Explanation: please mark me as the brainliest |
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| 13. |
The pH value of 0.025 molar solution of Caustic Potassium? with steps |
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Answer» Answer: of either 0.025 or 0.05M CaCl2 and titrating the leachate with NAOH to pH 7.0–7.4. ... retained in the SOIL and in the entrained solution was displaced with MOLAR potassium NITRATE. |
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| 14. |
The pH value of 0.025 molar solution of Caustic Potassium |
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Answer» Explanation: |
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| 16. |
Find the electrode potential at 25°c forch3cooh c(aq) 0.05 mole / pt (h2)1 atm. |
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| 17. |
High potency artificial sweetner among the following is (a)aspartame (b)saccharin (c)sucralose (d)alitame |
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Answer» Answer: option d Explanation: Aspartame is made up of the 2 AMINO acids - aspartic acid and PHENYLALANINE. Alitame uses aspartic acid and ALANINE. It has a quite a good taste and less AFTERTASTE than Aspartame. It is also more stable under heat though not as good as some sweeteners in this regard. So far, unlike Aspartane, no SIDE effects have been reported. pls mark as brainliest |
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| 18. |
By Cris Cross method of oxygen and nitrogen formula |
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Answer» by CRISS CROSS METHOD it will make Explanation: no2 |
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| 20. |
Distinguish between Groups and periods of modernperiodic table. |
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Answer» Answer: Difference between groups and periodic table. Explanation: Groups:- 1. Vertical columns 2. 18 groups 3. If you go from from left to RIGHT in a periodic table, METALLIC character decreases. Periods:- 1. Horizontal rows 2. 7 periods. 3. If you MOVE from top to bottom in a periodic table, metallic character increases |
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| 21. |
What Is Uniformly Composition |
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Answer» Explanation: A homogeneous mixture is a mixture in which the COMPOSITION is uniform THROUGHOUT the mixture. ... A phase is any part of a sample that has a uniform composition and PROPERTIES. By definition, a pure SUBSTANCE or a homogeneous mixture CONSISTS of a single phase |
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| 22. |
Reason of lanthanide contraction is |
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Answer» Answer: The Lanthanide Contraction is CAUSED by a poor shielding effect of the 4f electrons. GD because as atomic NUMBER increases, the atomic radius DECREASES. Yb because it has a LARGER atomic number Explanation: |
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| 23. |
Calculate the no. Of photon emitted by a bulb of 100 watt having efficiency 80% in 10min and wavelength of photon is 310nm |
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Answer» EXPLANATION: efficiency is 80% so output power BECOMES 80W. ALSO P=nhc/wavelength×time.substituting VALUES we get n=7.5×10*12 |
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| 24. |
? Name a diatomic element. |
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Answer» Explanation: COMMON DIATOMIC Elementshydrogen H2 gas. nitrogen N2 gas. oxygen O2 gas. fluorine F2 gas. chlorine CL2 gas. bromine Br2 liquid. iodine I2 SOLID. |
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| 25. |
8. The properties of water are different from the properties ofthe elements of which it is formed. Discuss. |
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Answer» Answer: oxygen supporter of COMBUSTION when combined with HYDROGEN both elements form a new product CALLED water....when so FORMED their properties get CHANGED so water is not supporter of water |
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| 26. |
Limitations of william synthesis |
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Answer» Answer: Limitations of the Reaction There are few limitations of Williamson Ether SYNTHESIS. Tertiary alkyl halides or sterically hindered PRIMARY or secondary alkyl halides tend to undergo E2 ELIMINATION in the presence of the alkoxide that in addition to being a nucleophile also act as a base. |
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| 27. |
state n+L rule?write the electronic configuration of element with atomic number 25 according to this rule?? |
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Answer» Explanation: I think this is CORRECT answer if it is correct mark it as BRAINLIEST |
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| 28. |
At constant pressure , The volume offixed mass of gas kept at 300 K is 10 L . Ifthe temperature is 600 K , What will be thenew volume ? Which law is related ? |
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| 29. |
NumericalsHow many atoms are required to prepare 60g of HNO3 chemistry class 9Numerical 1.7 |
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Answer» Answer: Mr of HNO3 is 1+14+3*16 = 63 60/63 = #of moles = 0.952380952 0.952380952 * #Avogadro’s = #of molecules = 5.7142857x10^23 5.7142857x10^23 X #of ATOMS in ONE molecule = #of atoms = 2.8571429x10^24 atoms Explanation: |
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| 30. |
A sample of Mg was burnt in air to give a mixture of MgO and Mg3N2. The ash was dissolved in 60 meq of HCl and the resulting solution was back titrated with NaOH. 12 meq of NaOH were required to reach the end point. An excess of NaOH was then added and the solution distilled. The ammonia released was the trapped in 10 meq of acid. Back titration of this solution required 6 meq of base. Calculate the % of Mg burnt to the nitride.________________________________________________________________________________ |
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Answer» Answer: 12meq Explanation: MARK me as BRAINLIEST |
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| 31. |
Nitrogen is a gas at room temperature while phosphorous is a solid .Explain |
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Answer» The size of nitrogen is quite small. As a result two nitrogen atoms can be linked to each other by three covalent bonds in ORDER to complete the octets of both the nitrogen atoms. This diatomic molecule N2 is very stable and has very negligible attraction towards other diatomic nitrogen molecules. Thus there is weak interaction between nitrogen molecules. So nitrogen exist as gas. While phosphorus being large in size has less tendency to form three bonds. Therefore, P atoms COMPLETES octets by sharing its VALENCE electrons with three other P atoms. As a result, it exist as tetratomic P4 molecule. In white phosphorous there is network which holds the phosphorous atoms together. This catenation tendency of phosphorus is REASON why it exist as solid. |
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| 32. |
In order to double concentration keeping volume constant, one must add 2 kg of NaOH in solution.What will be molarity and normality of 14% WN KOH solution at 298 K respectively?(a) 1.4 M, 2.8 N (b) 2.5 M, 2.5 N (C) 2.8 M, 1.4 N Id) 2 M, 2 N |
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Answer» Answer: Solutes should be dried before being weighed and made up, to the VOLUME REQUIRED , with solvent. Water QUALITY |
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| 33. |
What will be normality of 1 M KMnO4 solution ? [Guj. Board-2007)(a) 0.1 N(b) 2N(c) 100N(d) 5 N |
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Answer» 4Mn2++16F−→4MnF4−+4e−→ CHANGE of 4e− Molarity of KMnO4=0.025m Normality = Molarity× n-factor =0.025×4 =0.1N |
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| 34. |
How washing soda is used in paper Industry . What is d reason behind this ??? |
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Answer» Answer: washing soda is used as cleaning agents in domestic PURPOSES LIKE washing clothes. in fact it is sodium carbonate is a COMPONENT of many dry soap powders . it is used to dry permanent hardness of water so it is used in paper industries as well as in GLASS COMPANIES |
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| 35. |
Why freezing point of a solution is less than that of a pure solvent |
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Answer»
why freezing POINT to a SOLUTION is less than that of a pure solvent? ❐ The freezing point of solution is less means the solution must be COOLED down to a lower temperature than the pure solvent. It occurs because of being solid and decreases entropy. The resulting liquid solution has a lower freezing point because of chemical POTENTIAL of the solvent in the MIXTURE. |
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| 36. |
How learn formulas of chemistry |
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Answer» FIRST UNDERSTAND THE CONCEPT |
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| 37. |
What will be the change in the colour and life of iron and copper due to rusting . Explain |
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Answer» Answer: DUE TO THE ATMOSPHERIC CHEMICAL THE REACTIONS HAPPENS THE COLOUR OF IRON WILL BE REDDISH BROWN AND THE COLOUR OF COPPER WILL BE GREY IT HAPPENS BECAUSE OF THE MOISTURE PRESENT IN THE AIR. Explanation: LIKE KARO.. |
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| 38. |
If 5gm mixture of (Al+zn) is treated with hcl to form 1gm of H2 then find percentage of Al and Zn in mixture |
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| 39. |
How I will confirm that the particular element is in the form of any physical state |
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Answer» outside looks, COLOUR,TEMPERATURE, shape,DENSITY,change of state, change in colour |
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| 40. |
Name 15 acid radicals with their formula and valency. |
Answer» CHECK it on GOOGLE you can GET your answer. |
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| 41. |
Silver mirror is a test forAldehydesThio alcoholsAminesEthers |
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Answer»
D is the answer tollen's test MIRROR test using ammoniacal SILVER nitrate I HOPE it will be HELPFUL for you
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| 42. |
Give reason the smell of hot sizzling food reaches you several metres away.but to get smell from cold food you need to come closer |
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Answer» the REASON BEHIND this is in the hot food particles of air flow freely but in in COLD food the particles of food get trapped with each other |
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| 43. |
What effect does the concentration of H+ [aq] ions have on the nature of the solution |
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Answer» hope it HELPS u!! Explanation: The concentration of H+ (aq) ions determines the ACIDIC nature of the solution. HENCE, the acidity of a solution INCREASES with increases in the concentration of H+(aq) ions and vice versa... |
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| 44. |
white colour powder used by boctors to support fractured bone. when this white powder is mixed with water a hard solid mass is obtained. write balanced chemical equation . |
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Answer» this is the WRIGHT answer MARK me as BRAINLIEST |
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| 45. |
Puun, dl WILL(a) 1000PPM 01 low lue Toni(b) 200(c) 250What will be normality of 1 M KMnO4 solution ? [Guj. Board-2007)(d) 400(a) 0.1 N(b) 2 N(c) 100N(d) 5 N |
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| 47. |
Can azithro n levoflox be given as combination |
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| 48. |
Write a composition in three paragraphs on how your dream of possessing your very own camera came true when you were pestering people to pose for you and describe some of the interesting snaps you had taken. 200 words |
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Answer» Answer: 3 PARAGRAPHS!!!!!!!!!!!!!!!! |
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| 49. |
0.701g of silver salt of a dibasic acid on ignition yielded 0.497g of metallic silver. Molecular weight of the acid is? |
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Answer» by POAC of ag 2moles of ag2a = MOLES of ag 2(0.701 / 216+a ) = 0.497 / 108 1.402 / 216+a = 0.497/108 1402 / 216+a = 497 / 108 216+a = 304.66 a=88.66 |
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