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. |
If 50 calorie are added to a system and system does work of 30 calorie on surroundings, the change in internal energy of system is: |
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Answer» 20 cal |
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| 2. |
if 50 atoms of carbon reacts with 200 molecules of oxygen, find out the correct statement(s) |
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Answer» `O_2` is the limiting reagent |
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| 3. |
If 50 calorie are added to a system and system does wark of 30 calorie on surroundings, the change in internal energy of system is |
| Answer» Answer :D | |
| 4. |
If 5% sugar solution is isotomic with 1% solution of unknown substance, then find out molecular mass of unknown substance. |
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Answer» |
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| 5. |
If 5 liters of H_(2)O_(2) produce 50 liters of O_(2) at NTP , H_(2) O_(2) is |
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Answer» `'50V'` |
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| 6. |
If 4g of O_(2) diffuse through a very narrow hole, how much H_(2) would have diffused under identical conditions ? |
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Answer» Solution :`( 4g//t)/(X//t) = SQRT((2)/( 32))` ( x is the AMOUNT of `H_(2)` diffused and t is the time ) `( 4)/( x) = sqrt((1)/( 16)) = ( 1)/( 4)` |
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| 7. |
If 4.5 gm Aluminium completely reacts with 4gm of oxygen. Then what will be empirical formula of aluminium oxide. |
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Answer» `Al_(2)O` `n_(Al)=(4.5)/(27)=(1)/(6) n_(o_(2))=(4)/(52)=(1)/(8)(n_(Al))/(n_(o))=(1)/(6)xx(4)/(1)=(2)/(3)` `n_(o)=2xxn_(o_(2))=(1)/(4) "FORMULA"=Al_(2)O_(3)` |
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| 8. |
If 400 gm radioactive Iodine is taken initially. Then calculate the amount the ""(53)I^(128)(t_((1)/(2))="25 min") left after 75 minutes |
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Answer» |
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| 9. |
If 4-methyl-2-pentene is refluxed with dilute sulphuric acid, hydration reaction takes place.On principle, how many different alcohols would be formed ? |
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Answer» |
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| 10. |
If 4 g of NaOH dissolved in 36 g of H_(2)O, calcualte the mole fraction of each component in the solution. Also, determine the molarity of solution (specific gravity of solution is "1 g mL"^(-1)) |
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Answer» Solution :`"4 g NAOH"=(4)/(40)"mole"="0.1 mole"` `"36 g "H_(2)O=(36)/(18)"mole = 2 mole"` `THEREFORE " Mole fraction of "H_(2)P=1-0.047=0.953(or(2)/(2+0.1)=0.95)` `"Total mass of solution "="Mass of solvent "+"Mass of solution"=36+4g=40g` `"Volume of solution"=("Mass")/("Sp. gravity")=("40 g")/("1 g mL"^(-1))=40mL=0.040L` `"MOLARITY of solution "=("Moles of solute")/("Volume of solution in L")=("0.1 mole")/("0.040 L")=2.5M` |
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| 11. |
If 36 g. of Al is deposited at the cathode, the number of moles of electrons used is |
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Answer» 1 |
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| 12. |
If 340 g of mixture N_2 and H_2 in the correct raito gave a 20% yield of NH_3. The mass produced would be: |
| Answer» Answer :D | |
| 13. |
If ‘I’ is the intensity of absorbed light and C is the concentration of AB for the photochemical processthe rate of formation of A + hv to AB^(**) is directly proportional to : |
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Answer» C |
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| 14. |
If 32 g of O_(2)contain 6 022 xx 10^23 molecules at NTP then 32 g of S, under conditions, will contain, |
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Answer» `6.022 XX 10^(23)` S |
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| 15. |
If 30mL of H_(2) and 20mL of O_(2) react to form form water, what is left at the end of the reaction? |
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Answer» 10mL of `H_(2)` |
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| 16. |
If 30mL of H_(2) and 20mL of O_(2), reacts to form H_(2)O, what is left at the end of the reaction? |
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Answer» 10mL of `H_(2)` `{:(,"Initially", 30, 20,0),(,"After the reaction",0,(20-15),30):}` |
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| 17. |
If 3.01xx10^(20) molecules of H_(2)SO_(4) are removed from 98mg of H_(2)SO_(4). Then number of moles of H_(2)SO_(4) left are: |
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Answer» `0.1xx10^(-3)` mol `=5xx10^(-4)` `=0.5xx10^(-3)` Initial number of moles of `H_(2)SO_(4)=(0.098)/(98)=0.001=10^(-3)` REMAINING moles of `H_(2)SO_(4)=10^(-3)-0.5xx10^(-3)=0.5xx10^(-3)` |
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| 18. |
If 30g of a solute of molecular weight 154 is dissolved in 250g of benzene, what will be the boiling point of the resulting solution under atmospheric pressure . The molal boiling point elevation constant for benzene is 2.61^(@)C.m^(-1) and the boiling point of pure benzene is 80.1^(@)C |
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Answer» Solution :Suppose the elevation in B.p. is `DeltaT_(b)` Molality `=(DeltaT_(b))/(K_(b))=(DeltaT_(b))/(2.61)` …………(Eqn . 8) Moles of solute `=(30)/(154)` `:.` molality `=(30)/(154)xx(1000)/(250)` moles / `1000g` of solvent Thus, `(DeltaT_(b))/(2.61)=(30)/(154)xx(1000)/(250)` `DeltaT_(b)=2^(@)` Thus the b.p. of the resulting solution is `80.1+2=82.1^(@)C` |
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| 19. |
If 30% of an organism's DNA is thymine, then : |
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Answer» 70% is purine |
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| 20. |
If 3.01 xx 10^(28) molecules are removed from 98 mg of H_2SO_4, then number of moles of H_2SO_4 left are |
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Answer» `0.5 xx 10^(-3)` MOL `=1 xx 10^(-3)` No. of moles of `3.01 xx 10^(20)` molecules of `H_(2)SO_(4)` `=(3.01 xx 10^(20))/(6.02 xx 10^(23))=(1)/(2) xx 10^(-3)` `"Moles of" H_(2)SO_(4) "left"=(1 xx 10^(-3)-0.5 xx 10^(-3))` `=0.5 xx 10^(-3)` |
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| 21. |
If 30 ml of H_(2) and 20ml of O_(2) reacts to form water, what is left at the end of the reaction |
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Answer» 10 ml of `H_(2)` 1 mole `(1)/(2)` mole 1 mole 1 VOLUME `(1)/(2)` volume 1 ml `H_(2)` REACTS with `(1)/(2)`ml `O_(2)` 30 ml of `H_(2)` reacts with `=(1)/(2)xx30=15ml" "O_(2)` (20-15)=50ml of `O_(2)` will left at the end of the reaction. |
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| 22. |
If 30 ml of H_(2) and 20 ml of O_(2) react to form water, what is left at the end of the reaction? |
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Answer» `"10 ML of "H_(2)` `"2 ml of "H_(2)" REACT with 1 ml of "O_(2)." Hence, 30 ml of "H_(2)" will react with 15 ml of "O_(2)` |
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| 23. |
If 30 mL of H_(2) and 20 mL of O_(2) reacts to form water, what is left at the end of the reaction? |
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Answer» 10 mL of `H_(2)` 2 mole of `H_(2)` reacts with 1 vol of `O_(2)` to give water. Therefore, 30 mL of `H_(2)` will reacts with 15 mL of `O_(2)` to give water. Here, `H_(2)` is the LIMITING REACTANT. Volume of `O_(2)` left unreacted = 20-15=5 mL |
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| 24. |
If 30% of a first order reaction is completed in 12 mins, what percentage will be completed in 65.33 mins? |
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Answer» Solution :Give data : Time taken for COMPLETION of 30% of the reaction = 12 mins. a = 100 , x = 30 , a - x = 70 and t = 12 min Formula : `K =(2.303)/(t)"log"(a)/(a-x)` Solution : For a first order reaction, `=(2.303)/(12)"log"(100)/(70)` `=(2.303)/(12)xx0.1.549=0.02972 "min"^(-1)` `k=2.97xx10^(-2)"min"^(-1)` If t = 65.33 minutes, x = ? `k=(2.303)/(65.33)"log"(100)/(100-x)` `0.02972 = (2.303)/(65.33)"log"(100)/(100-x)` `"log"(100)/(100-x)=(0.02972xx65.33)/(2.303)=0.8430` `(100)/(100-x)` = Antilog of 0.8430 `100 = 6.966 (100 -x)` `100 = 696.6-6.966 x` `-6.966 x = 100 - 696.6=596.6` `x=(596.6)/(6.966)=85.62%` The reaction completed in 65.33 minutes |
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| 25. |
If 30 ml of H_2and 20 ml of O_2react to formwater, what is left at the end of the reaction ? |
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Answer» 10 ml of `H_2` 2 vol. of `H_2` react with 1 vol of `O_2` to give WATER ` therefore ` 30 ml of `H_2` will react with 15 ml of `O_2` Hence of `H_2` is a limiting REACTANT vol of `O_2` left unreacted = 20 - 15 = 5 ml |
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| 26. |
If 3 gm of glucose (mol. wt. 180) is dissolved in 60 gm of water at 15^(@)C. Then the osmotic pressure of this solution will be |
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Answer» 0.34 ATM |
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| 27. |
If 3/4 quantity of a radioactive element disintegrates in two hours, its half-life would be |
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Answer» 1 hours Thus `t = (2.303)/(0.693) XX t_(1//2) "log"(N_(0))/(N)` |
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| 28. |
If 3//4 quantity of a radioactive element disintegrates in two hours, its half life would be |
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Answer» 1 hours |
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| 29. |
If 2L of Cl_(2) gas and 2L of ClF_(3) gas react to form 6L of a pure gaseous compound at the same conditions of temperature and pressure, what is the molecular formula of the compound formed? |
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Answer» `ClF` |
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| 30. |
If 2.7 gm aluminum metal is deposited on electrodes when two different electrolytic cell having molten Cu(NO_(3))_(2) and Al(NO_(3))_(3) respectively are arranged in series, then how much copper metal is produced ? (Cu=63.5,Al=27.0" gm "mol^(-1)). |
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Answer» 9.525 gm So, 3 F electricity GIVES 27 gm of Al, but Al is produced only 2.7 gm So, FARADAY `=(2.7)/(27)xx3=0.3` Faraday Reaction : `Cu^(2+)+2E^(-) to Cu` So 2 F electricity gives 63.5 gm of Cu So, 0.3 F electricity gives `=(0.3xx63.5)/(2)` `=9.525gm` Cu |
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| 31. |
If 250 ml of 0.25 M NaCl solution is diluted with water to voluem of 500 ml, the new concentration of the solution is : |
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Answer» 0.167 M `0.25 M xx 250 ML M_(2)xx500ml` `:.M_(2)=(0.25xx250)/(500)=0.125M` |
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| 32. |
If 25 gram of Na_(2)SO_(4) is dissolved in 10^(3) kilogram solution, then concentration will be ……. |
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Answer» 25 ppm |
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| 33. |
If 224 ml of a triatomic gas has a mass of 1 g at N.T.P., then the mass of one atom is : |
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Answer» `9.3 xx 10^(-23) G ` 22400 ml of gas weigh ` = (1)/(224) xx 22400= 100 g ` ` THEREFORE ` molecular mass of gas= 100 mass of one molecule ` = (100)/(6.02 xx 10^23)` mass of atom ` = (100)/(6.02 xx 10^23) xx 1/3 ` (triatomic gas) = `5.53 xx 10^(-23) g ` |
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| 34. |
If 22.4 ml of a triatomic gas has a mass of 0.048 gat 273K and 1 atm pressure, then the mass of one atom is: |
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Answer» `7.9 xx 10^(-23) g ` ` = (0.048)/(22.4) xx 22400 = 48 g ` ` therefore ` 1 MOL of gas = 48 g Mass of ONE atom `= (48)/(3 xx 6.02 xx 10^23) = 2.6 xx 10^(-23) g ` |
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| 35. |
If 2.0g of a radioactive isotope has a half-life of 20 hr, the half-life of 0.5 g of the same substance is |
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Answer» 20 hr |
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| 36. |
If 201 persons are sitting in a row AB and if we release NO_(2) (laughing gas) from the side A and tear gas (molecular weight - 176) from side B, then which person will have a tendency to laugh and weep simultaneously? |
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Answer» `151^(ST)` from A |
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| 37. |
If 200ml of 0.2M HgCl_(2) solution is added to 800ml of 0.5M Kl (100% dissociated) solution. Assuming that the following complex formation taken place to 100% extent. |
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Answer» Solution :`{:(HgCl_(2),+,4KI,rarr,K[HgI_(4)],+,2KCl.),(40,,400,,0,,0),(0,,400-160,,40,,80),(,,(240)/(1000),,(40)/(1000),,(80)/(1000)):}` `PI=(i_(1)C_(1)+i_(2)C_(2)+i_(3)C_(3))RT`. `=(0.24xx2+3xx0.04+0.08xx2)0.082xx300.=18.69` atm. Other METHOD : `{:(HgCl_(2),+,4KI,hArr,K[HgI_(4)],+,2KCl.),(40,,400,,0,,0),(0,,400-160,,40,,80),(,,(240)/(1000),,(40)/(1000),,(80)/(1000)):}` `pi=(i_(1)C_(1)+C_(2)+i_(3)C_(3))RT`. `=(0.24xx2+xx0.04+0.08xx2)0.082xx300.=18.69` atm. |
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| 38. |
If 200 ml of 0.1 MH_2SO_4 salution is mixed with 200 ml of 0.15 M NaOH solution then heat evolve during the neutralization process is |
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Answer» 411 cal |
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| 39. |
If 20.0 g of CaCO_(3) is treated with 20.0 g of HCl, how many grams of CO_(2) will be produced ? |
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Answer» Here, `CaCO_(3)` will be the limiting reactant. |
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| 40. |
If 20% nitrogen is present in a compound its molecular weight will be , |
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Answer» 0.144 |
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| 41. |
If "20.0 g mL"^(-1) of "1.0 M CaCl"_(2) and "60.0 cm"^(3) of "0.20 M CaCl"_(2) are mixed, what will be the molarity of the final solution? |
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Answer» |
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| 42. |
If 20.0 g of CaCO_3is treated with 200 g of HCI, how many grams of CO_2can be obtained according to the following reaction : CaCO_3(s) + 2HCl(aq)toCaCl_2(aq) + H_2O (l) + CO_2(g) |
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Answer» Solution :`CaCO_3 `is the limiting REAGENT 100 g of `CaCO_3` produces `CO_2 = 44g ` 20g of `CaCO_3` will GIVE `CO_2 = 44/100 xx 20` = 8.8 g |
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| 43. |
If 20% nitrogen is present in a compound, its minimum molecular weight can be: |
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Answer» 144 |
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| 44. |
If 20 ml of0.5M Na_(2).SO_(4) is mixed with 50ml of 0.2M H_(2)SO_(4) & 30 ml of 0.4M Al_(2)(SO_(4))_(3) solution. Calculate [Na^(+)],[H^(+)].[SO_(4^(2-))],[Al^(3+)]. [Assuming 100% dissociation] |
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Answer» Solution :Molarity`=("moles")/("VOLUME")=10M`. Moles of `Na_(2)SO_(4)` `rArr20m`. Moles of `Na^(+)` (i) `therefore[Na^(+)]=(20)/(100)=0.2M` (ii) `[H^(+)]=?` `10m`. Moles `H_(2)SO_(4)` 20M. Moles `H^(+)` `[H^(+)]=(20)/(100)=0.2M` (iii) `[SO_(4)^(2-)]=(10+10+36)/(100)=(56)/(100)=0.56M` (iv) `[Al^(3+)]=(24)/(100)=0.24M` `rarr` Derive a relationship between molarity of a solution in which `w GM` of solute of molar MASS `M g//mol` is dissolved in ` W g` solvent `&` density of resulting solution`=d' g//ml`. say `1 L` solution taken, mass of `1 lit` solution `=(1000 d) g` moles of solute `=("molarity") x m` `therefore=(("molarity")xx1000)/(1000d-"molarity"xxM.Wt)` [Where no, of moles of solute `= "molarity")` |
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| 45. |
If 20 g. of sodium hydroxide is dissolved in 1 dm^(3) of water, the molarity of the solution will be |
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Answer» 0.5 |
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| 46. |
If 20 ml of 0.25N strong acid and 30 ml of 0.2 N of strong base are mixed, then the resulting solution is |
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Answer» 0.25 N basic `thereforeN=(N_(1)V_(1)+N_(2)V_(2))/(V_(1)+V_(2))=(20(0.25)+30(0.2))/(20+30)` `=(5+6)/(50)=(11)/(50)=0.2N` basic. |
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| 47. |
If 20 ml of methane (CH_4) is burnt using 50 ml of oxygen. The volume of the gases left after cooling to room temperature will be: |
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Answer» 60 ml |
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| 48. |
If 20 cc of methane in burnt using 50 cc of oxygen, the volume of the gases left after cooling to room temperature is |
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Answer» 60 cc |
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| 49. |
If 2 moles of MnO_(4)^(-) completely oxidizes 2.5 moles of M^(+), where the MnO_(4)^(-) reduces to Mn^(2+), then the product M^(+) is |
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Answer» `MO_(3)^(-)` |
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| 50. |
If 2 faraday current is pass through CuSO_(4) solution then find out how much copper can be deposited on cathode ? [Cu=63.5 gm "mole"^(-1)] |
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Answer» 0 gm `Cu_((aq))^(2+)+2E^(-) to Cu_((S))` . . . (Cathodic reduction) 2 mole `e^(-) to ` 1 MOL COPPER So 2F current produce 63.5 gm copper |
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