Explore topic-wise InterviewSolutions in Current Affairs.

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 concentration of hydrogen ion is a measure of acidity or alkalinity of a solution. A convenient way of expressing the hydrogen ion concentration of a solution is, in terms of the pH scale devised by Sorenson's . The pH of a solutionis defined as the negative logarithm of active concentration of H^(+) ions to the base 10 i.e., pH =- log_(10)[HI^(+)] or [H^(+)]=10^(-pH) At 25^(@)C (i) if pH lt1 , then solution is acidic (ii) if pH=7, then solution is neutral (iii) if pH gt 7, then the solution is basic Total [H^(+)]and [OH^(-)] in a mixture of strong acids or bases are represented in terms normality, which is equal to final number of milliequivalents of H^(+) or OH^(-) present in millilitre of solution Since H_(2)O ionizes as H_(2)O hArrH^(+)+OH^(-) Ionic product of water , K_(w)=[H^(+)][OH^(-)] ...(i) Taking log on both sidesin equation (i), we find pH +pOH=pK_(w) For neutral solution, pH =pOH:. 2pH =pK_(w) :. pH =1.2pK_(w) Since dissociationof water is an endothermic process, so temperature willhave great effect on K_(w) as well as on the pH of solution i.e., the nature of the soluiton . K_(w) at different temperature are related as under. ln (K_(w2))/(K_(w1))=(DeltaH)/(R)[(1)/(T_(1))-(1)/(T_(2))] At T_(1)K=T_(2)K, K_(w_(2))=K_(w1) (i) pH mixture of monoprotic weak acid is calculated as under : pH of monoprotic weak acid i.e., CH_(3)COOH {:(,CH_(3)COOH,hArr,CH_(3)COO^(-),+,H^(+)),("at "t=0,C,,0,,0),("at "t=t,C-alpha,,C alpha,,Calpha):} :. K_(a)=(C alpha xx C alpha)/(C-Calpha)=(alpha^(2)C)/(1-alpha) When a le0.1 , 100 alpha =1-alpha=1 :. K_(a)=(alpha^(2)C)/(1) [When (1-alpha)=1] alpha=sqrt((K_(a))/(C)):. [H^(+)]=alphaC=sqrt(K_(a)xxC) (ii) pH of a mixture of monoprotic weak acids is calculated as follows [H^(+)]=sqrt(K_(a1)C_(1)+K_(a2)C_(2)). where K_(a1) and K_(a2) are dissociation constants of monoprotic weak acids HA and HB acid C_(1) and C_(2) are their concentrations respectively. (ii) pH of polyproticweak acid, say H_(3)A-a triprotic weak acid having dissociation constants K_(a1).K_(a2) and K_(a3) where K_(a1) gt gt K_(a2) gt gt K_(a3). Then in that case , maximum [H^(+)] will be contributed from step I, and neglibily small from concentration of species producing from step III will be negligible with respect to steop II and similarly concentration of species producig from step II will be negligible with respect to step I. Based upon the above discussion, answer the following questions. A basic mixture of 100mL of M//20 NaOH and 200mL of M//10 Ca(OH)_(2) is mixed with 200 mL of M//10 H_92)SO_94) and finally the whole mixture is diluted to 100mL then the pH of the resulting solution will be

Answer»

`12.0`
`10.5`
8
None

Answer :A
2.

The concentration of hydrogen ion is a measure of acidity or alkalinity of a solution. A convenient way of expressing the hydrogen ion concentration of a solution is, in terms of the pH scale devised by Sorenson's . The pH of a solutionis defined as the negative logarithm of active concentration of H^(+) ions to the base 10 i.e., pH =- log_(10)[HI^(+)] or [H^(+)]=10^(-pH) At 25^(@)C (i) if pH lt1 , then solution is acidic (ii) if pH=7, then solution is neutral (iii) if pH gt 7, then the solution is basic Total [H^(+)]and [OH^(-)] in a mixture of strong acids or bases are represented in terms normality, which is equal to final number of milliequivalents of H^(+) or OH^(-) present in millilitre of solution Since H_(2)O ionizes as H_(2)O hArrH^(+)+OH^(-) Ionic product of water , K_(w)=[H^(+)][OH^(-)] ...(i) Taking log on both sidesin equation (i), we find pH +pOH=pK_(w) For neutral solution, pH =pOH:. 2pH =pK_(w) :. pH =1.2pK_(w) Since dissociationof water is an endothermic process, so temperature willhave great effect on K_(w) as well as on the pH of solution i.e., the nature of the soluiton . K_(w) at different temperature are related as under. ln (K_(w2))/(K_(w1))=(DeltaH)/(R)[(1)/(T_(1))-(1)/(T_(2))] At T_(1)K=T_(2)K, K_(w_(2))=K_(w1) (i) pH mixture of monoprotic weak acid is calculated as under : pH of monoprotic weak acid i.e., CH_(3)COOH {:(,CH_(3)COOH,hArr,CH_(3)COO^(-),+,H^(+)),("at "t=0,C,,0,,0),("at "t=t,C-alpha,,C alpha,,Calpha):} :. K_(a)=(C alpha xx C alpha)/(C-Calpha)=(alpha^(2)C)/(1-alpha) When a le0.1 , 100 alpha =1-alpha=1 :. K_(a)=(alpha^(2)C)/(1) [When (1-alpha)=1] alpha=sqrt((K_(a))/(C)):. [H^(+)]=alphaC=sqrt(K_(a)xxC) (ii) pH of a mixture of monoprotic weak acids is calculated as follows [H^(+)]=sqrt(K_(a1)C_(1)+K_(a2)C_(2)). where K_(a1) and K_(a2) are dissociation constants of monoprotic weak acids HA and HB acid C_(1) and C_(2) are their concentrations respectively. (ii) pH of polyproticweak acid, say H_(3)A-a triprotic weak acid having dissociation constants K_(a1).K_(a2) and K_(a3) where K_(a1) gt gt K_(a2) gt gt K_(a3). Then in that case , maximum [H^(+)] will be contributed from step I, and neglibily small from concentration of species producing from step III will be negligible with respect to steop II and similarly concentration of species producig from step II will be negligible with respect to step I. Based upon the above discussion, answer the following questions. How much volume of 10^(-2) M HCl should be added to 100mL of 10^(-2) M NaOH solution so that its pH changes by one unit ?

Answer»

9.9 ML
1.5 mL
7 mL
8 mL

Answer :A
3.

The concentration of hydrogen ion is a measure of acidity or alkalinity of a solution. A convenient way of expressing the hydrogen ion concentration of a solution is, in terms of the pH scale devised by Sorenson's . The pH of a solutionis defined as the negative logarithm of active concentration of H^(+) ions to the base 10 i.e., pH =- log_(10)[HI^(+)] or [H^(+)]=10^(-pH) At 25^(@)C (i) if pH lt1 , then solution is acidic (ii) if pH=7, then solution is neutral (iii) if pH gt 7, then the solution is basic Total [H^(+)]and [OH^(-)] in a mixture of strong acids or bases are represented in terms normality, which is equal to final number of milliequivalents of H^(+) or OH^(-) present in millilitre of solution Since H_(2)O ionizes as H_(2)O hArrH^(+)+OH^(-) Ionic product of water , K_(w)=[H^(+)][OH^(-)] ...(i) Taking log on both sidesin equation (i), we find pH +pOH=pK_(w) For neutral solution, pH =pOH:. 2pH =pK_(w) :. pH =1.2pK_(w) Since dissociationof water is an endothermic process, so temperature willhave great effect on K_(w) as well as on the pH of solution i.e., the nature of the soluiton . K_(w) at different temperature are related as under. ln (K_(w2))/(K_(w1))=(DeltaH)/(R)[(1)/(T_(1))-(1)/(T_(2))] At T_(1)K=T_(2)K, K_(w_(2))=K_(w1) (i) pH mixture of monoprotic weak acid is calculated as under : pH of monoprotic weak acid i.e., CH_(3)COOH {:(,CH_(3)COOH,hArr,CH_(3)COO^(-),+,H^(+)),("at "t=0,C,,0,,0),("at "t=t,C-alpha,,C alpha,,Calpha):} :. K_(a)=(C alpha xx C alpha)/(C-Calpha)=(alpha^(2)C)/(1-alpha) When a le0.1 , 100 alpha =1-alpha=1 :. K_(a)=(alpha^(2)C)/(1) [When (1-alpha)=1] alpha=sqrt((K_(a))/(C)):. [H^(+)]=alphaC=sqrt(K_(a)xxC) (ii) pH of a mixture of monoprotic weak acids is calculated as follows [H^(+)]=sqrt(K_(a1)C_(1)+K_(a2)C_(2)). where K_(a1) and K_(a2) are dissociation constants of monoprotic weak acids HA and HB acid C_(1) and C_(2) are their concentrations respectively. (ii) pH of polyproticweak acid, say H_(3)A-a triprotic weak acid having dissociation constants K_(a1).K_(a2) and K_(a3) where K_(a1) gt gt K_(a2) gt gt K_(a3). Then in that case , maximum [H^(+)] will be contributed from step I, and neglibily small from concentration of species producing from step III will be negligible with respect to steop II and similarly concentration of species producig from step II will be negligible with respect to step I. Based upon the above discussion, answer the following questions. At temperature 150^(@)C, for pH =7, the nature of the solution will be

Answer»

BASIC
ACIDIC
stll NEUTRAL
FIRST it will be acidic, after SOMETIMES it will be neutral

Answer :A
4.

The concentration of hydrogen ion is a measure of acidity or alkalinity of a solution. A convenient way of expressing the hydrogen ion concentration of a solution is, in terms of the pH scale devised by Sorenson's . The pH of a solutionis defined as the negative logarithm of active concentration of H^(+) ions to the base 10 i.e., pH =- log_(10)[HI^(+)] or [H^(+)]=10^(-pH) At 25^(@)C (i) if pH lt1 , then solution is acidic (ii) if pH=7, then solution is neutral (iii) if pH gt 7, then the solution is basic Total [H^(+)]and [OH^(-)] in a mixture of strong acids or bases are represented in terms normality, which is equal to final number of milliequivalents of H^(+) or OH^(-) present in millilitre of solution Since H_(2)O ionizes as H_(2)O hArrH^(+)+OH^(-) Ionic product of water , K_(w)=[H^(+)][OH^(-)] ...(i) Taking log on both sidesin equation (i), we find pH +pOH=pK_(w) For neutral solution, pH =pOH:. 2pH =pK_(w) :. pH =1.2pK_(w) Since dissociationof water is an endothermic process, so temperature willhave great effect on K_(w) as well as on the pH of solution i.e., the nature of the soluiton . K_(w) at different temperature are related as under. ln (K_(w2))/(K_(w1))=(DeltaH)/(R)[(1)/(T_(1))-(1)/(T_(2))] At T_(1)K=T_(2)K, K_(w_(2))=K_(w1) (i) pH mixture of monoprotic weak acid is calculated as under : pH of monoprotic weak acid i.e., CH_(3)COOH {:(,CH_(3)COOH,hArr,CH_(3)COO^(-),+,H^(+)),("at "t=0,C,,0,,0),("at "t=t,C-alpha,,C alpha,,Calpha):} :. K_(a)=(C alpha xx C alpha)/(C-Calpha)=(alpha^(2)C)/(1-alpha) When a le0.1 , 100 alpha =1-alpha=1 :. K_(a)=(alpha^(2)C)/(1) [When (1-alpha)=1] alpha=sqrt((K_(a))/(C)):. [H^(+)]=alphaC=sqrt(K_(a)xxC) (ii) pH of a mixture of monoprotic weak acids is calculated as follows [H^(+)]=sqrt(K_(a1)C_(1)+K_(a2)C_(2)). where K_(a1) and K_(a2) are dissociation constants of monoprotic weak acids HA and HB acid C_(1) and C_(2) are their concentrations respectively. (ii) pH of polyproticweak acid, say H_(3)A-a triprotic weak acid having dissociation constants K_(a1).K_(a2) and K_(a3) where K_(a1) gt gt K_(a2) gt gt K_(a3). Then in that case , maximum [H^(+)] will be contributed from step I, and neglibily small from concentration of species producing from step III will be negligible with respect to steop II and similarly concentration of species producig from step II will be negligible with respect to step I. Based upon the above discussion, answer the following questions. 2g NaOH is added to 100mL of M//20 H_(2)SO_(4) solution and the resulting solution is obtained by additino of 900 mL of wter, then what will be the pH of the solution ?

Answer»

12.6
1.4
10.6
2.4

Answer :A
5.

The concentration of hydrogen ion is a measure of acidity or alkalinity of a solution. A convenient way of expressing the hydrogen ion concentration of a solution is, in terms of the pH scale devised by Sorenson's . The pH of a solutionis defined as the negative logarithm of active concentration of H^(+) ions to the base 10 i.e., pH =- log_(10)[HI^(+)] or [H^(+)]=10^(-pH) At 25^(@)C (i) if pH lt1 , then solution is acidic (ii) if pH=7, then solution is neutral (iii) if pH gt 7, then the solution is basic Total [H^(+)]and [OH^(-)] in a mixture of strong acids or bases are represented in terms normality, which is equal to final number of milliequivalents of H^(+) or OH^(-) present in millilitre of solution Since H_(2)O ionizes as H_(2)O hArrH^(+)+OH^(-) Ionic product of water , K_(w)=[H^(+)][OH^(-)] ...(i) Taking log on both sidesin equation (i), we find pH +pOH=pK_(w) For neutral solution, pH =pOH:. 2pH =pK_(w) :. pH =1.2pK_(w) Since dissociationof water is an endothermic process, so temperature willhave great effect on K_(w) as well as on the pH of solution i.e., the nature of the soluiton . K_(w) at different temperature are related as under. ln (K_(w2))/(K_(w1))=(DeltaH)/(R)[(1)/(T_(1))-(1)/(T_(2))] At T_(1)K=T_(2)K, K_(w_(2))=K_(w1) (i) pH mixture of monoprotic weak acid is calculated as under : pH of monoprotic weak acid i.e., CH_(3)COOH {:(,CH_(3)COOH,hArr,CH_(3)COO^(-),+,H^(+)),("at "t=0,C,,0,,0),("at "t=t,C-alpha,,C alpha,,Calpha):} :. K_(a)=(C alpha xx C alpha)/(C-Calpha)=(alpha^(2)C)/(1-alpha) When a le0.1 , 100 alpha =1-alpha=1 :. K_(a)=(alpha^(2)C)/(1) [When (1-alpha)=1] alpha=sqrt((K_(a))/(C)):. [H^(+)]=alphaC=sqrt(K_(a)xxC) (ii) pH of a mixture of monoprotic weak acids is calculated as follows [H^(+)]=sqrt(K_(a1)C_(1)+K_(a2)C_(2)). where K_(a1) and K_(a2) are dissociation constants of monoprotic weak acids HA and HB acid C_(1) and C_(2) are their concentrations respectively. (ii) pH of polyproticweak acid, say H_(3)A-a triprotic weak acid having dissociation constants K_(a1).K_(a2) and K_(a3) where K_(a1) gt gt K_(a2) gt gt K_(a3). Then in that case , maximum [H^(+)] will be contributed from step I, and neglibily small from concentration of species producing from step III will be negligible with respect to steop II and similarly concentration of species producig from step II will be negligible with respect to step I. Based upon the above discussion, answer the following questions. On decreasing the temperature , the pH of the solution

Answer»

will INCREASE
will decrease
first PH will increase, then it will decrease
None of these

Answer :A
6.

The concentration of hydrogen ion in water is

Answer»

8
`1 xx 10^(-7)`
7
43472

Solution :`[H^(+)][OH^(-)] = 10^(-14), (10^(-7))(10^(-7)) = 10^(-14)`.
7.

The concentration of hydrogen ion [H^(+)] in 0.01 M HCl is

Answer»

`10^(12)`
`10^(-2)`
`10^(-1)`
`10^(-12)`

Solution :`[H^(+)]` CONCENTRATION in 0.01 M HCL is `10^(-2)` M because 0.01 M HCl have only `H^(+)`.
`Hcl H^(+) + CL^(-)`.
8.

The concentration of H_(2)SO_(4) in a botal labelled ''conc. Sulphuric acid'' is 18 M. The solution has a density of "1.84 g cm"^(-3). What is the mole fraction and weight percentage of H_(2)SO_(4) in this solution?

Answer»


Solution :`"Conc. = 18 MOL L"^(-1)." Solute = 18 moles "=18xx98 g = 1764g,"Solution "=100cm^(3)=1840g.`
`"Solvent "=1840-1764 = 76g`
`"Mole FRACTION of "H_(2)SO_(4)=(18)/(76//18+18)=0.81" ,Weight "%=(1764)/(1840)xx1000=95.87.`
9.

The concentration of H_(2)SO_(4) in a bottle labelled ''conc. Sulphuric acid '' is 18 M. The solution has a density of 1.84gcm^(-3). What is the mole fraction and weight percentage of H_(2)SO_(4) in this solution?

Answer»

Solution :`"Conc. = 18 mol L"^(1)`. SOLUTE = 18 moles `=18xx98g=1764g`, Solution = 1000 `cm^(3)` = 1840 g.
Solvent = `1840 - 1764 = 76 g`
`"Mole FRACTION of "H_(2)SO_(4)=(18)/(76//18+18)=0.81",WEIGHT"%=(1764)/(1840)xx1000=95.87.`
10.

The concentration of H^(+) ion in a sample of soft drink is 3.8xx10^(-3)M. Its pH is :

Answer»

`3.42`
`4.58`
`2.42`
`3.82`

SOLUTION :`pH=-log(3.8xx10^(-3))`
`=-[log3.8+log10^(-3)]`
`=-[(0.58)+(-3.0)]=2.42`
11.

The concentration of [H^(+)] and concentration of [OH^(-)] of a 0.1 aqueous solution of 2% ionised weak acid is [Ionic product of water = 1 xx 10^(-14)]

Answer»

`2 xx 10^(-3) M` and `5 xx10^(-12)M`
`1 xx 10^(3)` and `3 xx 10^(-11) M`
`0.02 xx 10^(-3) M` and `5 xx 10^(-11) M`
`3 xx 10^(-2) M` and `4 xx 10^(-13) M`

ANSWER :A
12.

The concentration of glucose (in g/litre) solution which is isotonic with a solution of urea containing 6 g per litre will be :

Answer»

6
34.2
18
1.8

Solution :For TWO non-electrolytic solution `C_(1) = C_(2)`
`W_(1)/(M_(1) xx 1)=W_(2)/(M_(2) xx 1 ) `
`:. 6/(60 xx 1) = W_(2)/(180 xx 1 ) :. W_(2) = (180 xx 6)/60 =18`
13.

The concentration of [H^+] and concentration of [OH^(-) ] of a 0.1 aqueous solution of 2% ionised weak acid is ionic product of water = 1 xx10^(-14)]

Answer»

`2 xx 10^(-3)`M and` 5 xx 10^(-12)M`
`1 xx 10^(-3)M and5 xx 10^(-12) M`
`0.02 xx 10^(-3)M and5 xx 10^(-11) M`
`3 xx 10^(-2)M and4 xx 10^(-13) M`

Solution :`[H^+] = C alpha= 0.1 xx 0.02= 2 xx 10^(-3)M`
( Asdegreeof dissociation=2 % = 0.02)
hence ` [OH^-]= (10^(14))/(2 xx 10^(-3)) =5XX 10^(-12) M`
14.

The concentration of glucose (in g/litre)solution which is isotonic with a solution of urea containing 6 g per litre will be:

Answer»

6
34.2
18
1.8

Answer :C
15.

The concentration of fluoride, lead, nitrate and iron in a water sample from an underground lake was found to be 1000 ppb, 40 ppb, 100 ppm and 0.2 ppm, respectively. This water is unsuitable for drinking due to high concentration of

Answer»

Lead
NITRATE
Iron
Fluoride

Solution :HIGHER CONCENTRATION is of nitrate (100 PM)
16.

The concentration of electrolyte required to coagulate a given amount of As_(2)S_(3) solution is minimum in case of

Answer»

POTASSIUM SULPHATE
ALUMINIUM nitrate
Magnesium nitrate
Potassium nitrate

Answer :B
17.

The concentration of C_(4)H_(9)Cl (n-butyl chloride) at different times are given. Calculate the average rate for the hydrolysis of n-butyl chloride. C_(4)H_(9)Cl + H_(2)O to C_(4)H_(9)OH + HCl

Answer»

SOLUTION :Average rate of reaction in the interval `t_(1)` to `t_(2)` = `({[C_(4)H_(9)Cl]_(t_(2))-[C_(4)H_(9)Cl]_(t_(1))})/(t_(2)-t_(1))`
18.

The concentration of electrolyte required to coagulate a given amount of As_(2)S_(3) sol is minimum in the case of

Answer»

magnesium nitrate
potassium nitrate
potassium sulphate
aluminium nitrate

Solution :ACCORDING Hardy-Schulze rule, for the coagulation of a negative SOL, the flocculating POWER of `K^(+),Mg^(+2) and Al^(+3)` ions is in order,
`Al^(+3) GT Ba^(+2) gt K^(+)`
19.

The concentration of an organic compound in chloroform is 6.15" g per "100" mL" of the solution. A portion of this solution in a 5 cm polarimeter tube causes an observed rotation of -1.2^(@). What is the specific rotation of the compound ?

Answer»

Solution :Specific ROTATION `=(100xxalpha)/(lxxc)=(100xx(-1.2))/(0.5xx6.15)=-39^(@)(L=5" cm "=0.5" dm")`
`ALPHA`= angle of rotation
l = length of the tube in dm
c = concentration of the solution in `g//100` ML
20.

The concentration of an organic compound in chloroform is 6.15 g per 100 mL of solution . A portion of this solution in a 5 cm polarimeter tube causes an observed rotation of -1.2^(@) . What is the specific rotation of the compound

Answer»

`+ 12^(@)`
`- 3.9^(@)`
`-39^(@)`
`+ 61.5^(@)`

ANSWER :C
21.

The concentration of an aqueous solution of 0.01 M CH_(3)OH solution is very nearly equal to which of the following

Answer»

`0.01% CH_(3)OH`
`0.01m CH_(3)OH`
`x_(CH_(3)OH)=0.01`
`0.01N CH_(3)OH`

Solution :For METHYL alcoholN = M.
22.

The concentration of an aqueous solution of glucose is 10% W/V. How much solution is required to dissolve 1 mole glucose ?

Answer»

18 litre
9 litre
0.9 litre
1.8 litre

SOLUTION :`10% W//V=(180xx100)/(X)`
x = 180 mL = 1.8 litre.
23.

The concentration of Ag^(+) ion in a given saturated solution of AgCl at 25^(@)C is 1.06xx10^(-5)g ion per litre. Thus, the solubility product of AgCl is :

Answer»

`0.353xx10^(-10)`
`0.530xx10^(-10)`
`1.12xx10^(-10)`
`2.12xx10^(-10)`

Solution :`K_(sp)=[AG^(+)][CL^(-)]`
`[Ag^(+)]=1.06xx10^(-5)`
and `[Cl^(-)]=1.06xx10^(-5)`
`K_(sp)=(1.06xx10^(-5))xx(1.06xx10^(-5))`
`=1.12xx10^(-10)`
24.

The concentration of a solution is expressed in terms of mole fraction, molarity, molality andin____

Answer»

SOLUTION : PERCENTAGES
25.

The concentration of a solution contaning 23g of phosphorous in 315g CS_(2) is 2.34 mol kg^(-1). The formula of phesphorous is (at mass of P=31)

Answer»

`P_(6)`
`P_(4)`
P
`P_(2)`

ANSWER :C
26.

The concentration of a reactant in a solution falls (i) from 0.2 to 0.1 M in 2 hrs (ii) from 0.2 to 0.05 M in 4 hrs. The order of hydrolysis of the reactant is

Answer»

zero
two
one
half

Solution :As half-life PEROID REAMINS CONSTANT, ORDER = 1
27.

The concentration of a reactant X decreases from 0.1 M to 0.025 M in 40 minutes. If the reaction follows I order kinetics, the rate of the reaction when the concentration of X is 0.01 M will be

Answer»

`1.73xx10^(-4)"M min"^(-1)`
`3.47xx10^(-4)"M min"^(-1)`
`3.47xx10^(-5)"M min"^(-1)`
`1.73xx10^(-5)"M min"^(-1)`

Solution :`K=(2.303)/(t)"log"(A_(0))/(A)=(2.303)/(40)"log"(0.1)/(0.005)`
`=(2.303)/(40)log 20 = 0.075`
Rate of the reaction when the concentration of X is 0.01 M will be
`0.075xx0.01=7.5xx10^(-4)M min^(-1)`.
Note : No OPTION is correct in the GIVEN question.
28.

theconcentrationof areactantin a solutionfalls(i)from0.2 to 0.1 M in2 hrs,(ii )from0.2to 0.05 m in4 hrs, theorderof thehydrolysisof thereactant is

Answer»

zero
two
one
HALF

SOLUTION :Halflifein REMAINING same.
29.

The concentrationof a reactantdecreasesfrom0.2M to 0.1M in10minutes. Therateof thereactionis ______.

Answer»

`0.01 M`
`10^(-2)`
`0.01` mol `DM^(-3) "MIN"^(-1)`
1 mol` dm^(-3) "min"^(-1)`

Solution :RATE of REACTION = `(dx) /(dt) = [(0.2 - 0.1)/(10)] = (0.1)/(10)`
`0.01` mol `dm^(-3) "min"^(-1)`.
30.

The concentration of a reactant changes from 0.03 M to 0.02 M in 25 minutes . The average rate of reaction using time in seconds is :

Answer»

`0.4xx10^(-3) "mol L"^(-1) s^(-1)`
`0.024 "mol" L^(-1)s^(-1)`
`0.24 "mol " L^(-1)s^(-1)`
`0.66xx10^(-4) "mol"L^(-1) s^(-1)` .

Solution :(D) Rate `=-(DELTA[R])/(Deltat)=(-(0.02-0.-03))/(24"min")`
`=0.4 xx10^(-3) "mol L"^(-1) min^(-1)`
`=0.4xx10^(-3) "mol L"L^(-1) min^(-1) `min /60 s
`=0.66 xx10^(-4) "mol L"^(-1) s^(-1)`
31.

The concentration of a 100 ml solution containing xg of Na_(2)CO_(3) (molecular wt=106) is YM.The value of X and Y are respectively

Answer»

2.12 , 0.05
1.06 , 0.2
1.06 , 0.1
2.12 , 0.1

Answer :C
32.

The concentration in g//L of a solution of cane sugar (Molecular weight = 342) which is isotonic with a solution containing 6 g of urea (Molecular weight = 60) per litre is

Answer»

`3.42`
`34.2`
`5.7`
19

Solution :ISOTONIC solution `=(w_(1))/(m_(1)V_(1))=(w_(2))/(m_(2)V_(2))`
`=(w_(1))/(342xx1)=(6)/(60xx1)=(342xx6)/(60)=34.2`.
33.

The concentraion of free HN_3 in a 0.01 M solution of KN_3 if K_a=1.9xx10^(-5) is :

Answer»

2.3 mol/mL
3.3 mol/mL
4.3 mol/mL
5.3 mol/mL

Answer :a
34.

The concentration in gms per litre of a solution of cane sugar ( M =342) which is isotonic wih a solution containing 6 gms of urea ( M = 60 ) per litreis

Answer»

3.42
34.2
5.7
19

Solution :ISOTONIC solution has same MOLARITY ( Concentration ) .
`m_(2) = m_(1)`
`(g_(2))/( M_(2)) =(g_(1))/( M_(1))`
`( X )/( 342) =( 6)/( 60)`
35.

The compund 'A' is

Answer»




ANSWER :D
36.

The compression factor (compressibility factor) for one mole of a van der Waals' gas at 0^(@)C and 100 atmosphere pressure is found to be 0.5. Assuming that the volume of a gas molecule is negligible, calculate the van der Waal's constant 'a'.

Answer»

Solution :`Z=(PV)/(RT) =0.5`
`therefore (100xxV)/(0.082xx273)=0.5`
`therefore V=0.112` litre
Now, USING van der Waals. equation
`[P+(a)/(V^(2))][V]=RT`
or `[P+(a)/(V^(2))]=(RT)/(V)" "(therefore` b is negligible)
`therefore [100+(a)/((0.112)^(2))]=(0.082xx273)/(0.112)`
`=199.88`
`therefore (a)/((0.112)^(2))=99.88`
`therefore a=1.253" litre"^(2)" mole"^(-2)` atm.
37.

The compressibility of a gas is less than unity at S.T.P. Therefore :

Answer»

`V_m` GT 22.4 LITRES
`V_m` LT 22.4 litres
`V_m` = 22.4 LITRE
`V_m` = 44.8 litres

Answer :B
38.

The compressibility factor (Z) of one mole of a va der Waals gas of negligible a value is

Answer»

1
`(bP)/(RT)`
`1+(bP)/(RT)`
`1-(bP)/(RT)`

Solution :As PER the vander Waals equation
`(P+a/(V^(2)))(V-b)=RT`
If a is negligible then `a/(V^(2))~~0`
`:.P(V-b)=RTimpliesPV-PB=RT`
`IMPLIES(PV)/(RT)-(Pb)/(Rt)=1impliesZ=1+(Pb)/(RT)`
(Z, COMPRESSIBILITY factor `=(PV)/(RT)`)
39.

The compressibility factor for N_(2) at - 50^(@)C and 800 atmp pressure is 1.95 and at 100^(@)C and 200 atmp, it is 1.10. A certain mass of nitrogen occupied one litre at - 50^(@)C and 800 atmp. Calculate the volume occupied by the same quantity of N_(2) at 100^(@)C and 200 atmp.

Answer»


ANSWER :3.77L
40.

The compressibility factor of an ideal gas is :

Answer»

0
1
2
4

Answer :B
41.

The compressibility factor of gases is less than unity at STP. Therefore,

Answer»

`vm GT 22.4 ` LITRES
`vm lt 22.4 ` litres
`vm = 22.4 ` litres
`vm = 44.8 ` litres

ANSWER :B
42.

The compressibility factor of a gas is defined as Z =(PV)/Nrt. The compressibility factor of an ideal gas is :

Answer»

zero
Infinite
1
-1

Answer :C
43.

The compressibility factor for definite amount of vander walls gas at 0^(@)C and 100 atm is found to be 0.5. Assuming the volume of gas molecules negligible the vander Waal's constant 'a' for gas in "litre"^(2)" mol"^(-2) atm is :

Answer»

1.256
0.256
2.256
10.0256

Solution :`Z=(PV)/(nRT) =0.5`
`(P+(n^(2)a)/(V^(2))(V-nb)=nRT)`
`RARR (P+(n^(2)a)/(V^(2))(V) =nRT` (b is negligible)
`therefore PV^(2) -nRTV +n^(2)a=0`
`V =(nRT pm SQRT(n^(2)R^(2)T^(2)-4n^(2)aP))/(2P)`
Since, V is constant at given P and T THUS discriminant is zero
`therefore n^(2)R^(2)T^(2)=4n^(2) aP`
`therefore
44.

The compressibility factor for H_2 and He is usally :

Answer»

GT 1
lt 1
1
Either of these

Answer :A
45.

Thecompressedgasaviailableincookinggascylinders isa mixtureof :

Answer»

`C_(6) H_(6) +C_(6) H_(5) CH_(3) `
`C_(2) H_(4) +C_(2) H_(2)`
`C_(2) H_(4) +CH_(4) `
`C_(4)H_(10)+C_(3)H_(8)`

Answer :D
46.

The compoung givenbelow is not antipyretic

Answer»

CHLORAMPHENICOL
aspirin
Ibuprofen
paracetamol

Answer :A
47.

The compounds with maximum and least ionic characters among the following are:

Answer»

`LICL and RBCL`
`RbCl and BeCl_2`
`RbCl and MgCl_2`
`MgCl_2 and BeCl_2`

ANSWER :B
48.

The compounds with highest ionic character in metal halides, highest stability in halogen acids and highest acidic strength in halogen acids respectively are :

Answer»

MI, HCl, HF
MF, HF, HI
HI, HCl, HBr
MF, HBr, HI

Answer :B
49.

The compounds with high heat of formation are less stable because

Answer»

HIGH temperature is required to SYNTHESISE them
Molecules of such compounds are distorted
It is DIFFICULT to synthesis them
ENERGY rich STATE leads to instability

Solution :Compounds with high heat of formation are less stable because energy rich state leads to instability.
50.

The compounds which react with dilute H_2SO_4 in presence of HgSO_4to form methylketone are-

Answer»

`PhC-=C""CH_3`
`CH_3C-=C""CH_3`

ANSWER :B::C::D