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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. |
The products of electrolysis of dilute aqua solution of sodium hydride is |
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Answer» Answer: Electrolysis of Aqueous NaCl Since water can be both OXIDIZED and reduced, it competes with the dissolved Na+ and Cl– ions. RATHER than producing sodium, hydrogen is produced. ... The NET PROCESS is the electrolysis of an aqueous solution of NaCl into industrially useful PRODUCTS sodium hydroxide (NaOH) and chlorine gas. |
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| 2. |
The activity per ml of a solution of radioactive substance x how much water be added to 200 ml of this solution so that the activity false to expire 20 per ml after 4 half life |
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Answer» You can USE the CONCEPT of both the HALF life and the activity to get to the required ANSWERS |
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| 3. |
The mass of oxalic acid crystals(h2c2o4.2h2o)required to prepare 50ml of a 0.2n solution is |
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Answer» Answer: 0.63 g is the mass of OXALIC acid crystals required to prepare 50 ML of a 0.2 N solution. Explanation: - Oxalic acid EXISTS as the dihydrate C₂H₂O₄.2H₂O. Molecular weight of oxalic acid dihydrate = 126 g / mol. Gram equivalent weight = Molecular weight / basicity = = 63 g / mol 1 Normal solution of oxalic acid should have 63 g in 1 L. 0.2 Normal solution of oxalic acid should have = 12.6 g in 1 L. 0.2 Normal solution of oxalic acid should have in 50 mL. = 0.63 g in 50 mL. |
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| 4. |
Teh number of gm of oxygen present in32.2 gm of na2so4.10h2o will be |
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Answer» NUMBER of GM of OXYGEN in 32.2 g na2so4.10h2o is No. of oxygen atoms in ONE molecule =4+10=14. ... Molar mass of Na2SO4.10H2O=46+32+64+180=322g/mol. ... 32.2g=32.2/322=0.1 mols32.2g=32.2/322=0.1mols. |
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| 5. |
The first emission line of balmer series in hydrogen spectrum has the wave number equal to |
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Answer» Explanation: The first emission LINE of brained series in Hydrogen SPECTRUM is in the balmer series APPEARS at- 1. 5R/36 /cm 2.3R/4/cm 3.7R/144/cm 4.9R/400/cm |
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| 6. |
Prove with an example that oxidation and reduction occur simultaneously |
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Answer» Answer: this happens because for oxidation to take place the ELECTRONS lost by the substance that is OXIDIZED MUST be accepted by ATOMS or ions of another substance. Also, for REDUCTION to occur the electrons gained by the substance that is being reduced must be transferred from the atoms of ions of another substance |
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| 7. |
The difference between nth and n+1th bohr orbits of h atom is equal to its |
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Answer» Explanation: r_n=\frac{n^2\times 52.9}{Z} (in pm) where, r_n = radius of n^{th} orbit n = number of orbit Z = ATOMIC number of HYDROGEN = 1 r_n-r_{n+1}=r_{n-1} \frac{(n+1)^2\times 52.9}{Z}-(\frac{(n)^2\times 52.9}{Z})=\frac{(n-1)^2\times 52.9}{Z} (n+1)^2-(n)^2=(n-1)^2 n = 4 |
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| 8. |
Potassium paramagnetic does not dissolve in water in ordinary temperature.a. True b. False |
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Answer» the CORRECT answer is - b.) false hope it HELPS......... |
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| 9. |
The activation energy of the reaction, a+b----> c+d+ 38kcal is 20kcal. What would be the activation energy of the reaction, c+d -----> a+b? |
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Answer» Explanation: The forward reaction is: A+B -----> C+D C+D -----> A+B MEANS "go backwards", or in the reverse. So if you are down at products, you have to go all the WAY up to the top of the PEAK (this is your energy of activation...to take your reactants and get them to the activated STATE), then that distance (in energy) is 58kcal. Hope it helps you... |
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| 10. |
O-bromobenzoic acid and o-nitrobenzoic acid is more acidity.Reasons |
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Answer» Explanation: Hey MATE Here's ur ans Br is electron donating grp WHEREAS nitro is electron withdrawing grp. |
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| 11. |
State the meaning of oxide in the chemical reaction considered the chemical reaction represented in the above equations and write the name of the substance oxidized reduce acid oxidation agent and reducing agent in the reaction mention above mn o2 + force hcl is equal to mncl2 + 2 h2o |
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Answer» Answer: In the reaction MnO2 + 4HCl -> MNCL2 + Cl2 + 2H2O , CL (chlorine) is the substance which is oxidized from the HCL, and it is the reducing agent for the MnO2 as well. As Cl is the oxidized substance in HCl, thus it is the oxidizing agent in the reaction. |
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| 12. |
Predict the products of electrolytes of an aqueous solution of agno3 with silver electrode .Write reaction that occurs at each electrode. |
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Answer» Explanation: · I wrote Ag+,NO3-,H+,OH-.Is it correct? ... Ag will DEPOSITE at CATHODE and Ag ELECTRODE will DISSOLVE at anode. ... NCERT Textbook Solutions for CLASS 12 Science Chemistry. |
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| 13. |
On heating calcium carbonate gets converted into calcium oxide and carbon dioxide |
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Answer» Calcium carbonate is strongly heated until it undergoes THERMAL decomposition to form calcium oxide and CARBON DIOXIDE. The calcium oxide (unslaked lime) is dissolved in water to form calcium HYDROXIDE (limewater) |
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| 14. |
Number of waves made by a boar electron in one complete revolution in fourth orbit is |
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Answer» Answer: λ = h/mu ….(ii) Substituting (ii) in (i), i GET! (h/λ) R = 3 (h/2π) 3λ = 2πr Easy method!! 3(3 - 1)/2 = 3 * 2/2 = 3 |
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| 15. |
The mass of 2.24×10-³ m³ of a gas is 4.4 g at 273.15K and 101.kPa pressure.the gas may be |
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Answer» Answer: The gas may be CARBON dioxide. Explanation: According to avogadro's LAW, 1 MOLE of EVERY substance occupies 22.4 L at NTP, weighs equal to the molecular mass and contains avogadro's number According to the ideal gas equation:' P = Pressure of the gas = 101 kPa = 0.99 atm V= Volume of the gas = T= Temperature of the gas = 273.15 K R= Gas constant = 0.0821 atmL/K mol n= moles of gas= ?
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| 16. |
Name the compound which is added to lower the fusion temperature of the electrolytic bath in the extraction of aluminium |
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Answer» Hello♥️ Cryolite is your answer. |
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| 17. |
Name an organic compound which is poisonous and contain oh age group |
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Answer» Answer: METHANOL is the organic compound comes under alcoholic group which is toxic and UNFIT for CONSUMPTION as high DOSE . |
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| 18. |
40liter of mixture contaion 10%of water how much water must b added to make 20% of water |
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Answer» Answer: So it contains 90% milk. So amount of milk in the mixture= 40 x0.9=36 LITER. Now on adding 'X' LITERS of water the % of water increases to 20% . Or the % of milk decreases to 80% |
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| 19. |
In the reaction n2+3h2 2nh3 the ratio by volume of n2 h2 and nh3 is 1:3:2 this illustrates the law of |
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Answer» reaction n2+3h2 2nh3 the ratio by VOLUME of n2 H2 and nh3 is 1:3:2 this ILLUSTRATES the LAW of Gay Lissa's law. Mark as Brainliest |
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| 20. |
Name the process of heating and o2 higher temperature in the presence of air |
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Answer» Explanation: When you eat, oxygen is OXIDIZING the food (FUEL) you INGESTED, to generate energy you need to live. So there is "combustion" going on inside you! The main BENEFIT of oxygen is that its the most commonly available oxidizer. The main component of AIR that support combustion is oxygen. |
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| 21. |
In no3- the number of bind pairs of electron around nitrogen atom is |
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Answer» Explanation: This is DENOTED by Number (4) This is denoted by a minus SIGN. The doubly-bonded O has on the average six electrons.So,it will be 4. Mark as BRAINLIEST. |
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| 22. |
If 4.9gm of the h2so4 solution is mixed with 4gm of naoh solution then ph of solution is |
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Answer» Answer: If 1 MOL OH- reacts with 1 mol H+, then 0.1 mol OH- will react ... The PH of the resultant solution is 13, which is consistent .... 4.9 gm of H2SO4 react with=4 gm NaOH. |
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| 23. |
Name name the compound formed by the reaction between calcium oxide and silica |
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Answer» HEYYY....... Calcium Silicate is FORMED by reaction of calcium OXIDE and silica hope it helps......... |
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| 24. |
Name an allotrope of a non metal which allows elecyricity to pass through it |
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| 25. |
How to calculate the equilibrium constant of cobalt amino complex? |
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Answer» Answer: Background Heteroligand CO(II) complexes involving imidazole and ... Such CALCULATIONS are NEEDED to drive further ... amino acid ligand-to-metal concentration RATIO. |
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| 26. |
Is the energy of h atom is -13.6 kilojoule the energy required to excite electron from ground state to second orbit is? |
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Answer» Answer: kJ mol^-1, then the energy REQUIRED to excite the electron from ground state to SECOND orbit is" plus 6299 more QUESTIONS from Chemistry. |
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| 27. |
How many moles of al2o3 will be formed when mixture of 5.4g of al and 3.2g of oxygen is heated? |
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Answer» Moles of oxygen gas = 3.2/(16*2) = 0.1 moleSo, from the reaction we GET 4 moles of Aluminium REACTS with 3 moles of oxygen. From the equation we know that 0.2 mol of aluminum will react with: We get that 3/4*0.2 = 0.15 mol of the oxygen gas. |
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| 28. |
In rhombic sulphur s atom are joined into s8 molecules with density 2.07 g/cc. Calculate no. Of s8 molecules in a crystal of 0.568mm()3 |
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Answer» 1.844 will be the answer. ...... |
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| 29. |
Name the process by which energy is prepared from chloride why it is called so process and write down the balance chemical equation |
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Answer» diatillation......... |
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| 30. |
If the electron of a hydrogen atom present in the first orbit the tital energy of the electron is |
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| 31. |
Name a solution reacts with crushed eyes xl to give a gas that lime water milky |
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| 32. |
If equivalent weight of metal is 10g then weight of metal hydride is |
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Answer» Answer: 100/10 = 10G ......... ..... |
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| 33. |
5 moles of oxygen is heated at constant volume from 10 to 20 what will be the change in internal |
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Answer» Answer: 10 + 30/5 = 40/5 = 8. ................ |
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| 34. |
How much energy is required to ionize a hydrogen atom if the electron occupies n=5 orbit? Ii compare tge answer with? |
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Answer» Explanation: By according to the QUESTION Z = ATOMIC number of the atom n = principal quantum number For ionization from n1 = 5 to .HOPE this would be helpful. |
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| 35. |
In the reaction twice into a5 giving 4 and o2 + o2 the rate of formation of an o2 at any time t was found to be 2.4 into 10 to the power minus 4 mole per litre per minute with rate constant 4.4 into 10 to the power minus 4 per minute hands rate of disappearance of n2o 5 at the same time t and the corresponding rate constant of the reactions respectively would |
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Answer» n2so4 will be the answer ... |
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| 36. |
How many lattice points are there in one unit cell of bcc lattice? |
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Answer» ANSWER: one unit CELL of a face-centered cubic has 8 lattice points at CORNERS and 6 lattice at faces. so, TOTALLY 14 lattice points. hope it helps :) |
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| 37. |
In permanganate and dichromate the transitional metal are in their highest oxidation state.That is they have d*0 configuration.However they are purple and orange colour respectievely.Why? |
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| 38. |
If the boiling point of oxygen argon and nitrogen are-183°c,186°c and-196°c respectively which gas will obtained at the uppermost level and which one at the lowest level during fractional distillation |
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Answer» uppermost level- OXYEN. |
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| 39. |
Identify the type of reaction in the digestion of food and heating of manganese dioxide with alumunium powder |
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Answer» DIGESTION is DECOMPOSITION REACTION. next reaction is DISPLACEMENT reaction |
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| 40. |
How many moles of nitrogen are there in 7.45 mole sample of ammmonium phosphate? |
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| 41. |
How many grams of iodine. Are present in a solution which require 40 ml of 0.11? |
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Answer» IODINE will be S2O32– + I2 → S4O62– + 2I–. Hope this HELPS you. |
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| 42. |
Hardness in water sampleis 300ppm. Caco3 then what is its molarity |
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Answer» Answer: HARDNESS is most commonly EXPRESSED as MILLIGRAMS of calcium carbonate equivalent PER litre. Water containing calcium carbonate at concentrations below 60 mg/l is generally CONSIDERED as soft; 60–120 mg/l, moderately hard; 120–180 mg/l, hard; and more than 180 mg/l, very hard (McGowan, 2000) |
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| 43. |
2g of base x requires 100ml of 0.4n acid for complete neutralisation .The eqhivalent weight of base is |
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Answer» Answer: 100 × 0.4/2 = 40/2 = 20 ...... .... |
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| 44. |
Give two reasons to justify water at room temperature and either almira is a solid |
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Answer» No they are at LIQUID ......... |
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| 45. |
Fresh milk has a ph of 6 when it changed to curd will its ph increases or decreases why |
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Answer» Answer: WELL, When it CHANGES to curd its pH will decrease. It is because curd contains lactic ACID. Since acids GENERALLY have a low pH value, when fresh milk changes to curd its pH will decrease. |
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| 46. |
Find the mass number of a uninegative ion having 10 neutrons and 10 electrons |
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Answer»
If we look at uninegative ION that means no.of electrons=no. Of protons -1.hence we have a formula A-Z=N where A=atomic MASS ... FOLLOW this you get answer. I hope you understand. |
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| 47. |
59g of silver salt of an organic acid of molar mass 210 on ignition gave .36g of pure silver the basicity of acid is |
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Answer» It is about 246.8 ................... |
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| 48. |
Explain why blue salt of copper sulphate is heated its come colour |
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Answer»
On heating the blue salt of copper sulphate it is seen that it becomes colourless. This is so because the salt strongly LOOSES all the water of crystallization, which LEADS to the FORMATION of anhydrous copper sulphate which is WHITE in colour. The salt containing water crystallization is CALLED hydrated salts. I hope you understand. |
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| 49. |
0g of a gas at 300k and 1atm occupies a volume of 4.0l what is molecular mass |
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Answer» Answer: 300/4 = 150/2 = 75 ........ |
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| 50. |
Give three ways in which the metal zinc differ from the non metal carbon at least one of the different must be a chemical difference |
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Answer» Some ways are - Zinc is METAL while CARBON is non metal whereas Zinc sulphides are reduced by roasting CARBONATES are reduced by calcination. |
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