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.
| 50901. |
8 grams of NaOH are totally consumed to react with carbondioxide produced by the calcination of sodium bicarbonate. What weight of sodium bicarbonate is to be calcinated? |
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Answer» |
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| 50902. |
8 gm O_(2) has the same number of molecules as in |
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Answer» 11 g `CO_(2)` same molecules IMPLIES same moles `(11)/(44)=(1)/(4),(7)/(28)=(1)/(4)` |
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| 50903. |
8 gm NaOH dissolve in 250 mL solution. This solution is diluted by using 500 ml water. Find the molartiy in' dilute solution. Also find moles of NaOH ? |
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Answer» |
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| 50904. |
8 gm H_2 and 256 gm HI in 4 L flask calculate this active mass. (H = 1 g "mol"^(-1), I = 127 g "mol"^(-1)) |
| Answer» SOLUTION :1 MOL `L^(-1) H_2`, 0.5 mol `L^(-1)` HI | |
| 50905. |
8 g of sulphur is burnt to form SO_(2) which is oxidised by chlorine water . The solution is treated with BaCl_(2) solution . The amount of BaSO_(4) precipitated is |
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Answer» 1 MOLE |
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| 50906. |
7g of nitrogen occupies a volume of 5 litres under certain conditions. Under the same conditions one mole of a gas, having molecular weight 56, occupies a volume of |
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Answer» 40L |
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| 50907. |
7g of nitrogen contains the same number of molecules as |
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Answer» 8g of oxygen |
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| 50908. |
7g of N_2 is allowed to react with 2g H_2 in presence of catalyst to form NH_3 Which is the limiting reagent? |
| Answer» SOLUTION :`N_2`-LIMITING REAGENT, | |
| 50909. |
7g of N_2 is allowed to react with 2g H_2 in presence of catalyst to form NH_3 Calculate the maximum amount of NH_3 that can be formed in the reaction. |
| Answer» SOLUTION :`NH_3=8.5g` | |
| 50910. |
750 mL of nitrogen are collected over water at 25^@C and 740 mm pressure. If the aqueous tension at this temperature is 23.8 mm Hg, calculate the mass of the dry gas. |
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Answer» SOLUTION :According to Dalton.s law of partial pressure, `P_(gas) = P_(obs). - " aqueous TENSION " = 740 - 23.8 = 716.2 mm Hg` The given gas thus occupies a volume of 750 mL at `25^@C " and " 716.2 mm Hg`. According to the ideal gas equation, `PV =nRT= m/M RT` `m=(PVM)/(RT)` In the present case, `P =716.2 mm = (716.2)/760 =0.9424` atm `V=750 mL = 0.750 L, "" T=25+273 =298 K` `M = 28 " and " R =0.0821 L " atm " K^(-1) mol^(-1)` `m=(0.9424xx0.750xx28)/(0.0821xx298) = 0.809 g` Hence, the mass of the given gas = 0.809 g |
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| 50911. |
7.5 g of an acid are dissolved per litre of the solution. 20 mL of this acid solution required 25 mL of N//15 NaOH solution for complete neutralisation. Calculate the equivalent mass of the acid. |
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Answer» Solution :Calculation of the normality of the acid Volume of acid taken = 20 ML volume of base required = 25 mL Normality of base `= N//15` Applying normality equation : `ubrace(N_(1)xxV_(1))_("Acid") equiv ubrace(N_(2) XX V_(2))_("Base")` `N_(1) xx (20 mL) = ((1)/(15) N) xx 25 mL` `N_(1) = ((1)/(15) N) xx ((25 mL))/((20 mL)) = (1)/(12) N` Step II. Calculation of the equivalent mass of the acid Amount of acid dissolved per litre of solution = 7.5 g `:.` Strength of the acid `= 7.5 g L^(-1)` Equivalent mass of the acid `= ("Strength of the acid")/("Normality of acid") = ((7.5 g L^(-1)))/((1//12 N)) = 90.0` |
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| 50912. |
7.5 g of a gas occupies a volume of 5.6 litres at 0^(@)C and 1 atm pressure. The gas is |
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Answer» NO `(7.5g)/(5.6L) xx22.4L=30G` Molar mass of NO (14+16) = 30g |
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| 50913. |
7.5 g of a gas occupies 5.6 litres as STP. The gas is |
| Answer» ANSWER :A | |
| 50914. |
74.5 g metal chloride contain 35.5 g chlorine. Then the equlvalent weight of metal is..... |
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Answer» 39 |
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| 50915. |
7.38 g of a sample of a metal oxide is quantitatively reduced to 6.84 g of pure metal. If the specific heat of the metal is 0.0332 cal/g, calculate the valency and the accurate atomic weight of the metal. |
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Answer» Solution :Let the formula of the oxide be `M_(2)O_(x)` , where x is the valency of the METAL M. We have, therefore, `x xx `moles of M = `2 xx` moles of O. We know that, atomic weight `xx` specific HEAT `~~` 6.4 (Dulong and Petit.s law) `:.` approximate atomic weight `= (6.4)/(0.0332) = 193 ` From EQN. `(1), x xx (6.64)/(193) =2xx ((7.38-6.84))/(16)` or x= 1.9. But valency is always a whole number and so the valency of the metal is 2. Now, to calculate the accurate value of the atomic weight of the metal, substitute the value of x as 2 in equation (1) again, or `2xx(6.84)/("atomic WT.") = 2xx((7.38 - 6.84))/(16)` Atomic weight (accurate) = 202.67. |
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| 50916. |
723 KJ mol""^(-1) heat is released when 1 molemethanol combustions in present of O_(2). What amount of heat is enlisted of one mole of O_(2) is used? |
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Answer» 241 kJ `CH_(3) OH_((l)) + (3)/(2) O_(2(g)) = CO_(2(g)) + 2H_(2) O_((l)) , DELTA H= -723` kJ 1 mole `(3)/(2)` mole therefore `(3)/(2)` moles `O_2` is used in this reaction. If 1 mole `O_2` is used. then free ENERGY `= (2)/(3) xx` combustion energy 723 `= 482` kJ |
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| 50917. |
720cc of methane diffused through a porous membrane in 30min. Under identical conditions 240cc of gas 'X'diffused in 20 min. Calculate the molecular weight of 'X'. |
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Answer» Solution :Rate of diffusion of methane ` = 720//30 = 24 "cc" m^(-1)` Rate of diffusion of gas .X.`240//20 = 12 "cc" m^(-1)` Ratio of rates of diffusion is GIVEN as `(r_(1))/(r_(2))= sqrt((M_(2))/(M_(1))) = (24)/(12) = 12` Molecular weight of .X. ` = 2^(2) XX 16 = 64` |
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| 50918. |
7.18 g iron displaces 2.04 g copper from copper sulphate solution. If the equivalent weight of copper is 31.7, calculate the equivalent weight of iron. |
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Answer» Solution :In the present case, MASS of IRON taken = 1.8 g Mass of copper displaced = 2.04 g Equivalent mass of copper = 31.7 Using the relation `=("Mass of iron")/("Mass of copper") = ("Equivalent weight of iron")/("Equivalent weight of copper") ` and substituting the VALUES, we have `1.8/2.04 = ("Equivalent weight of iron")/31.7` or Equivalent weight of iron `=(1.8 XX 31.7)/2.04= 27.97` |
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| 50919. |
70 g of a sample of magnesite on treatment with excess of HCl gave 11.2 L of CO_(2) at STP. The percentage purify of the sample |
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Answer» 80 |
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| 50920. |
7.00 g of a gas occupies a volume of 4.1 L at 300 K and 1 atm pressure. What is the molecular mass of the gas? |
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Answer» Solution :In the PRESENT case, `P= 1 " atm, " V= 4.1 L, T = 300 K, m= 7.0 g, " and " R=0.0821 L " atm " K^(-1) mol^(-1)` `:."" PV = m/M RT` `:."" M=(mRT)/(PV)= (7.0 xx0.0821 xx 300)/(1 x 4.1)= 42` AMU and `:. ""d = m/V` `:. "" d=(7.0)/(4.1)=1.7g L^(-1)` Hence, the molecular mass of the given gas is 42 amu and its density in the given conditions is`1.7 g L^(-1)`. |
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| 50921. |
70 gms of a metal oxide on reduction produced 54 gms of metal. The atomic weight of the metal is 81. What is its valency? |
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Answer» wt. of metal = 54 g `therefore` wt of oxygen = `70-54=16g` `(W_(1))/(W_(2))=(E_(1))/(E_(2)),("wt of metal")/("wt of oxygen")=("EQ wt of metal")/("EQ wt of oxygen")` `(54)/(16)=(E)/(8)impliesE=27` At. Wt = EQ wt `xx` valency `81=27xx` valency implies Valency = 3 |
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| 50922. |
7 grams of nitrogen is present at 127^@C and 16 grams of oxygen at 27^@C. Calculate (a) ratio of kinetic energy and (b) ratio of average kinetic energy of nitrogen and oxygen. |
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Answer» Solution :`(K.E) = 3/2 NRT ` For two gases ratio of KINETIC energies = ` ((K.E )_1)/((K.E)_2) = (n_1 T_1)/(n_2 T_2)= (7)/(28 ) xx 400 xx(32)/(16) xx (1)/(300 ) = 2:3` |
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| 50923. |
7 g of a sample of sodium chloride on treatment with excess of silver nitrate gave 14.35 g of AgCl. The percentage of NaCl in the sample is |
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Answer» 80 |
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| 50924. |
7-Bromo-1,3,5-cycloheptatriene exists as an ion whereas 5-bromo-1,3-cyclopentadiene does not form an ion even in presence of Ag^+. Explain |
Answer» Solution :7-Bromo-1,3,5-cycloheptatriene, on ionization, gives tropylium ion. Since , tropylium ion contains `6 PI`-electrons which are completely delocalized, therefore, according to Huckel rule, it is AROMATIC and HENCE stable .Being highly stable , it is easily FORMED . In contrast,5-bromo-1,3-cyclopentadiene, on ionization, will give 1,3-cyclopentadienyl cation which contains `4pi`-electrons and hence in antiaromatic. Being antiaromatic, it is highly unstable and hence is not formed even in the presence of `Ag^+` ion which otherwise facilitates ionization. |
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| 50925. |
6xx10^(22) gas molecules each of mass 10^(-24)kg are taken in a vessel of 10 litre. What is the pressure exerted by gas molecules? The average velocity of the gas molecules is 92.62m/sec. |
| Answer» Answer :d | |
| 50926. |
6L H_2O_2 contains 440 gm solute than how much litre O_2 gas will produce from this solution at STP ? |
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Answer» 24.16 `=440/(34xx6)=2.156 M H_2O_2` `V(O)_2`= M x 11.2 = 2.156 x 11.2 =24.16 L `O_2` GAS |
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| 50927. |
6g. of Urea is dissolved in 90g. of water. The mole fraction of solute is |
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Answer» `1//5` |
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| 50928. |
6g of NaOH are dissolved in 200 cm^3 of water. What is the relation between molarity and normality of the solution thus obtained ? |
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Answer» |
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| 50929. |
6g of Mg reacts with excess of an acid. The amount of hydrogen produced would be |
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Answer» 0.5g |
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| 50930. |
6g of hydrogen at 1.5 atm and 273^@C occupies a volume of |
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Answer» 44.8L |
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| 50931. |
""_(6)C^(12) and ""_(1)T^(3) are formed in nature due to the nuclear reaction of neutron with |
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Answer» `""_(7)N^(14)` |
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| 50932. |
6.9g N_2O_4 is taken 0.5 L closed vessel at 400 K temperature. The equilibrium N_2O_(4(g)) hArr 2NO_(2(g)) total pressure at equilibrium is 9.15 atm calculate K_c, K_p and partial pressure of each component. |
| Answer» SOLUTION :`p_(N_2O_4)`= 0.69 atm , `p_(NO_2)`= 8.46 atm , `K_p`=103.73 atm , `K_c=3.162 "MOL L"^(-1)` | |
| 50933. |
6.8 gm of H_2O_2 is present in 500 ml of an aqueous solution. When 10 ml of this solution is decomposed, what is the S.T.P. volume of oxygen obtained. |
| Answer» ANSWER :C | |
| 50934. |
66 gm sample of an oxalate salt Al_(x)H_(y)(C_(2)O_(4))_(z).nH_(2)O is dissolved in water to form 500mL solution. 50mL solution requires 60mL of 0.5M Ba(OH)_(2) and 240mL 0.1 M KMnO_(4) in acidic medium separately. If in salt x,y,z and n are present in simplest ratio, then select the correct statement(s). |
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Answer» MOLES of oxalate salt in original sample is 0.2 |
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| 50935. |
6.54 g of zinc are treated with 11.5 g of H_2SO_4. Calculate the volume of hydrogen evolved at S.T.P. How much H_2SO_4 will be left in excess? |
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Answer» Solution :The CORRESPONDING CHEMICAL equation is: `underset(65.38 g)(Zn) + underset(2.016 + 32.06 + 64.0= 98.1 g)(H_(2)SO_(4)) to ZnSO_(4) + underset(22.4 "L at S.T.P")(H_(2))` From the equation, it is clear that 6.54 g of zinc will react with 9.81 g of `H_2SO_4`. Thus, the amount of `H_2SO_4` TAKEN is in excess. Hence, Zn will get consumed completely and this is the limiting reagent. `therefore 65.38 g` of zinc EVOLVE `H_(2) = 22.4 L` at S.T.P. `therefore 6.54 g` of zinc will evolve `H_(2) = 22.4/(65.38) xx 6.54 = 2.24` L at S.T.P. Further, `therefore 65.38` g of zinc react with `=H_(2)SO_(4) = 98.1 g` `therefore H_(2)SO_(4)` left in excess `=11.5- 98.1 = 1.69 g` Hence, 2.24 L hydrogen will be evolved at S.T.R and 1.69 g of `H_2SO_4` will be left in excess. |
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| 50936. |
.^(64)Cu (hlaf lifre = 12.8h)deacays by beta^(-) emission (38%), beta^(+)- emission (19%) and electron capute (43%). Write the decay products and calculatepartial half-live for each of the decay processes. |
Answer» Solution :We know, Given `lambda_(av) = (0.693)/(12.8) hr^(-1)` `:. lambda_(1) +lambda_(2) +lambda_(3) =lambda_(av) = (0.693)/(12.8) = 5.41xx10^(-2) hr^(-1)` .....(1) ALSO for parallel PATH DECAY `lambda_(1)` = Fractionlal yield of `._(30)^(64)Zn xx lambda_(av)` `lambda_(2)` = Fractionalyeild of `._(28)^(64) Ni xx lambda_(av)` `lambda_(3)` = Fractionlal yield of `._(28)^(64) Ni xx lambda_(av)` `:. (lambda_(1))/(lambda_(2)) = (38)/(19)` ....(2) `(lambda_(1))/(lambda_(3)) = (38)/(43)` ....(3) From eqs. (1), (2) and (3) `lambda_(1) = 2.056xx10^(-2) hr^(-1)` `lambda_(2) = 1.028xx10^(-2) hr^(-1)` `lambda_(3) = 2.327xx10^(-2) hr^(-1)` `:. t_(1//2)` for `beta^(-)` emission `= (0.693)/(2.056xx10^(-2)) = 33.70 hr` `t_(1//2)` for `beta^(+)` emission `= (0.693)/(1.028xx10^(-2)) = 67.41 hr` `t_(1//2)` for electron capture `= (0.693)/(2.327xx10^(-2)) = 29.28 hr` |
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| 50937. |
6.46gm BaSO_(4) is obtain from 4.81gm compound in estimation of sulphur by Carius method. Calculat ethe % of sulphur |
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Answer» |
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| 50938. |
64 gm of CH_(4) "and" 68gm "of" H_(2)S was placed in an close container and heated up to 727^(@)C following equilibrium is established in gaseous phase reaction is: CH_(4)(g)+2H_(2)S(g)hArrCS_(2)(g)+4H_(2)(g) The total pressure at equilibrium is 1.6 atm and partial pressure of H_(2) "is" 0.8 atm. Then |
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Answer» Total moles at equilibrium `4.8` `{:(t=0,64gm,68gm),("Moles",4"mole",2"mole"):}` `4-x 2-2x x 4x` Total moles at equilibrium`=4-x+2-2x+x+4x=(6-2x)` ACC. To `PV=nRT,T=727+273=1000K` `1.84xxV=(6-2x)xxRxx1000 `....(1) For `H_(2) "gas" V,P_(H_(2))=n_(H_(2))RTto0.8xxV=4xxRxx1000` ....(2) From EQ (1) and(2) `(1.6)/(0.8)=((6-2x))/(4x)` `x=0.6` |
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| 50939. |
6.3 g of oxalic acid dihydrate have been dissolved in water to obtain a 250 ml solution. How much volume of 0.1 N NaOH would be required to neutralize 10 mL of this solution ? |
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Answer» 40 mL Normality of the solution prepared `N=(w xx 1000)/(E xx V) = (6.3 xx 1000)/(63 xx 250) = 0.4 N` `underset(NaOH)(N_(1)V_(1)) = underset("OXALIC acid")(N_(2)V_(2))` `therefore V_(1) = (N_(2)V_(2))/N_(1) =(0.4 xx 10)/0.1 = 40 mL` |
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| 50940. |
60mL of pure ozone is heated and then colled. The increase in the volume is 10mL. Determine the percentage volume of ozone decomposed into oxygen. |
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Answer» Solution :The balanced equations for the decomposed of ozone is `2O_(3)(g)to3O_(2)(g)` `2 vol "" 3vol"Gay-Lussac.s COEFFICIENTS"` `60mL "" "0mL at start"` `60-2x "" 3x "after the REACTION"` Total volume of the mixture after the reaction =60-2x+3x=60+10 SOLVING, x=10 Volume of `O_(3)` decomposed =20mL Percentage volume of `O_(3)` decomposed `=(20/(60)xx100=33.3%)` |
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| 50941. |
60g CH_(3)COOH and 46g C_(2)H_(5)OH react in 5L flask to form 44g CH_(3)COOC_(2)H_(5) at equilibrium. On taking 120 g CH_(3)COOH and 46g C_(2)H_(5)OH, CH_(3)COOC_(2)H_(5) formed at equilibrium is : |
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Answer» 44g Molar mass of `C_(2)H_(5)OH=46g mol^(-1)` Molar mass of `CH_(3)COOC_(2)H_(5)=88g mol^(-1)` `:. [CH_(3)COOH)_("Initial")=(60)/(60xx5)=0.2 "mol"L^(-1)` `[C_(2)H_(5)OH]_("Initial")=(46)/(46xx5)=0.2"mol" L^(-1)` `[CH_(3)COOC_(2)H_(5)]_(eqm)=(44)/(88)xx(1)/(5)=0.1 "mol" L^(-1)` `CH_(3)COOH+C_(2)H_(5)OH hArr CH_(3)COOC_(2)H_(5)+H_(2)O` Initial `0.2 M ""0.2M` At eqm. `(0.2-0.1)M""(0.2-0.1)M""0.1M""0.1M` `:. K=([CH_(3)COOC_(2)H_(5)][H_(2)O])/([CH_(3)COOH][C_(2)H_(5)OH])` `=(0.1xx0.1)/(0.1xx0.1)=1` In second case, `[CH_(3)COOH]_("Initial")=0.4M` `[C_(2)H_(5)OH]_("Initial")=0.2M` If x is the amount of acid and ALCOHOL reacted `[CH_(3)COOH]_("eqm.")=(0.40-x)M` `[C_(2)H_(5)OH]_("eqm.")=[0.2-x]M` `[CH_(3)COOC_(2)H_(5)]_("eqm.")=[H_(2)O]_("eqm.")=xM` `:. K=(x^(2))/((0.4-x)(0.2-x))=1` `:. x^(2)=(0.4-x)(0.2-x)` `x^(2)=0.08+x^(2)-0.6x` `0.6x=0.08` `x=(8)/(60)M` `:. `Moles of ethyl acetate produced `=(8)/(60)XX5=(2)/(3)` Mass of ethyl acetate produced `=(2)/(3)xx88=58=58.66g`. |
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| 50942. |
60g of a compound on analysis gave C=24g, H=4g and O=32g. Its empirical formula is |
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Answer» `C_(2)H_(4)O_(2)` |
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| 50943. |
6.048 g H_(2) and 28 g N_(2)react with each other and produce 34.048 g NH_(3). This reaction is explained by which law ? |
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Answer» CONSTANT PROPORTION |
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| 50944. |
6.023xx10^(22) atoms of Hydrogen can make |
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Answer» 0.05 MOLES of `H_(2)` molecules Hydrogen `(H_(2))` is diatomic 1 gram atom of any ELEMENT `=6.023xx10^(23)` atoms of that element Atomic weight of hydrogen = 1 Number of gram atoms = `("Weight in grams")/("Gramotomicweight")` |
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| 50945. |
6.023xx10^(20) molecules of urea are present in 100 ml of its solution. The concentration of the solution is |
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Answer» 0.001 M `6.023 xx 10^(23)` molecules in 1000 ml = 1 M `:. 6.023 xx 10^(20)` molecules in 1000 ml=`(1xx6.023xx10^(20))/(6.023xx10^(23))=10^(-3)` `10^(-3)` moles of PRESENT in 100 ml `:.` In 1000ml the moles present is=`10^(-3)/cancel(100)xxcancel(1000)=10^(-2)` moles CONCENTRATION = 0.01 M |
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| 50946. |
6.022 xx 10^(22) molecules of N_(2) at NTP will occupy a volume of |
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Answer» 22.4 LITRES |
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| 50947. |
6.022 xx 10^(20) molecules of urea are present in 100 mL of its solution. The concentration of urea solution is : |
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Answer» 0.001 M `(6.022xx10^(20))/(6.022xx10^(23))=0.001` MOL Concentration of solution `=((10^(-3)"mol"))/(("0.1 L"))xx10^(-2)"molL"^(-1)=0.01 M`. |
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| 50948. |
6.02 xx 10^(20) molecules of urea are present in 100 mL of its solution. The concentration of urea solution is: |
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Answer» 0.001 M `therefore` MOLARITY of solution `=10^(-3)/100 xx 1000 = 0.01 M` |
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| 50949. |
60 mL of methane and 180mL of oxygen are mixed and fixed. The resulting gases are passed throughcaustic soda solution. Determine the composition of gases before and after passing through base solution. |
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Answer» Solution :The storichiometric equation is `underset((g))(CH_(4))+underset((g))(2O_(2))tounderset((g))(CO_(2))+underset((l))(2H_(2))O` `1 vol 2 vol 1vol ovol """Gay-Lussac.s coefficients"` `60mL 180mL 0mL 0mL """ at start"` `0mL 60mL 60mL 0mL "" "after the reaction" ` Before passing through caustic soda solution unreacted oxygen =60mL Carbondioxide FORMED =80ML After passing through caustic soda solution(since `CO_(2)` is ABSORBED) unreaced oxygen =60mL |
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| 50950. |
60 gm of oleum (labelled as 118%) is mixed with 11.8 gm of water. What will be the composition of final mixture? |
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Answer» Only `H_(2)SO_(4)`, having MASS 71.8 gm |
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