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.

State the two motives of demand for money.

Answer»

1. Transaction motive: It relates to the desire of the people to hold cash for the current transactions.

Mt = f (y)

Precautionary motive: It relates to the desire of the people to hold cash to meet unexpected or unforeseen expenditures.

Mp = f (y)

Speculative motive: It relates to the desire of the people to hold cash in order to take advantage of market movements regarding future changes in the price of bonds and securities in the capital market.

Ms = f (i)

2.

Name some individuals who tried to estimate colonial India’s per capita income.

Answer»

Dadabhai Naoroji, William Digby, VKRV Rao and RC Desai made attempts to compute the per capita income in the colonial period.

3.

What were the motives behind deindustrialization by Britishers in India?

Answer»

The following are the two-fold motives behind the systematic deindustrialisation affected by the British:

1. Making India a Supplier of Raw Materials: The main motive of the British government was to make India a mere supplier of cheap raw materials to feed its own flourishing industrial base.

2. Making India a Market for Finished Goods: Another important objective of the British government was to use India as a virgin market to sell the finished goods produced by the British industries.

4.

Jayanti throws a pair of dice and records the product of the numbers appearing on the dice. Pihu throws 1 dice and records the squares the number that appears on it. Who has the better chance of getting the number 36? Justify?

Answer» For Jayanti,
Favourable outcome is (6,6) i.e, 1
Probability(getting the number 36) `= (1)/(36)`
For Pihu,
Favourable outcome is 6 i.e,
Probability(getting the number 36) `=(1)/(6)`
`therefore` Phiu has the better chance.
5.

What least number must be subtracted from 5224 to get a number exactly divisible by 43?1. 332. 233. 214. 37

Answer» Correct Answer - Option 3 : 21

Given:

The number = 5224

Formula used:

Dividend = (Divisor × Quotient) + Remainder

Calculation:

⇒ 5224 = (43 × 121) + 21

⇒ The number which is subtracted from 5224 = 5224 - (43 × 121) = 5224 - 5203 = 21

∴ The required result will be 21.

6.

A number is divided by 357, leaves the remainder 219. Find the remainder when the same number is divided by 17.1. 22. 93. 114. 15

Answer» Correct Answer - Option 4 : 15

Given: 

The divisor is 357 and the remainder is 219.

Calculation: 

Let the number is 'N'

According to question

N = 357k + 219

Now, this number is divided by 17

⇒ (357k + 219) ÷ 17

⇒ 357k/17 + 219/17

In, the part (357k/17) remainder is Zero, because 357 is divisible by 17

Now, we consider this part (219/17) 

Here, we found quotient is 12 and the remainder is 15

∴ The required value of the remainder is 15.

7.

The smallest whole number which is divisible by 3 and also by the next two greater prime number is1. 602. 1053. 214. 15

Answer» Correct Answer - Option 2 : 105

Given:

First number = 3

Next two greater prime numbers = 5 and 7

Concept used:

LCM will be the smallest number divisible by all of them

Calculation:

3 = 3 × 1

5 = 5 × 1

7 = 7 × 1

LCM will be the uncommon factors = 3 × 5 × 7

⇒ 105

∴ The smallest whole number divisible by 3, 5 and 7 is 105

8.

The smallest whole number which is divisible by 3 and also by the next two greater prime number is ____________.1. 602. 213. 104. 105

Answer» Correct Answer - Option 4 : 105

Given:

Number given = 3

Next two greater prime numbers = 5 and 7

Concept used:

LCM of prime numbers are the product  of these numbers

Calculation:

Required number = 3 × 5 × 7

⇒ 105

∴ The required number is 105

9.

If the sum of the squares of two positive numbers is 2426 and the square root of one number is 7, then the other number is:1. 62. 43. 54. 8

Answer» Correct Answer - Option 3 : 5

Given

The sum of the squares of two positive numbers = 2426

The square root of one number = 7

Calculation

Let numbers be x and y

⇒ √x = 7

⇒ x = 49

According to question

⇒ x2 + y2 = 2426

⇒ (49)2 + y2 = 2426

⇒ y2 = 2426 - 2401

⇒ y2 = 25

∴ The other number is 5

10.

Five bells begin to toll together at intervals of 9 seconds, 6 seconds, 4 seconds, 10 seconds and 8 seconds respectively. Starting together, how many times will the bells toll together in a span of 1 hour?1. 112. 123. 54. 10

Answer» Correct Answer - Option 1 : 11

Given:

Five bells commence tolling together and toll at intervals of 9, 6, 4, 10 and 8 seconds respectively.

Concept used:

Least common multiplication 

Calculation:

A least common multiple of (9, 6, 4, 10 and 8)

We can write 9 = 32

4 = 22 

6 = 2 × 3

8 = 23 

10 = 2 × 5

A least common multiple of (9, 6, 4, 10 and 8) = 23 × 32 × 5

⇒ 8 × 9 × 5

⇒ 360 sec

Bells ring together after every 360 sec 

Required number of times in 1 hour (60 × 60 seconds) = [(60 × 60)/360]

⇒ 10

But we have to add 1 because at starting all bells will be rung once a time after that the ring 10 times.

⇒ 10 + 1 

⇒ 11 times 

∴ The required number of times when they toll together is 11.

11.

What will be the product of any two prime numbers except the smallest prime number?A. Always zeroB. Always oneC. Always an even numberD. Always an odd number1. B2. C3. A4. D

Answer» Correct Answer - Option 4 : D

Given:

product of any two prime numbers except the smallest one

Calculation:

Prime numbers are 2, 3, 5, 7, ...

The smallest prime number is 2

So it can not be used in further calculation.

Product of any prime numbers,

Randomly picking from the above numbers,

⇒ 3 × 5 = 15

⇒ 11 × 9 = 99

and so on

Now we can say that the product will always be Odd number,

∴ The product will always be Odd number. 

12.

Find the value of 5231405 × 99999.A. 523135278595B. 723135268595C. 523135268595D. 6231352685951. D2. B3. C4. A

Answer» Correct Answer - Option 3 : C

Given:

5231405 × 99999.

Calculation:

5231405 × 99999.

⇒ 5231405 × (100000 – 1)

⇒ 523140500000 – 5231405

⇒ 523135268595

∴ The value of 5231405 × 99999 is 523135268595.

13.

If the sum of 2 numbers is 27 and their product is 182, find the numbers.1. 20 and 72. 15 and 123. 13 and 144. 19 and 8

Answer» Correct Answer - Option 3 : 13 and 14

Given 

a + b = 27 

ab  = 182 

Calculation 

Let the 1st number be a and the 2nd number will be 27 – a 

Therefore, their product = a (27 – a)

It is given that the product of these numbers is 182 

Therefore a (27 – a) = 182 

⇒ a2 – 27a + 182 = 0

⇒ a2 – 13a – 14a + 182 = 0

⇒ a(a – 13) – 14(a – 13) = 0

⇒ (a – 13) (a – 14) = 0

⇒ a – 13 = 0 or a – 14 = 0 

⇒ a = 13 or a = 14

If first number = 13, then

⇒ Other number = 27 – 13 = 14 

If first number = 14, then

⇒ Other number 27 – 14 = 13 

∴ Therefore the numbers are 13 and 14.

14.

4 bells ring at an interval of 4, 12, 20 and 25 minutes. If they ring together at 8 a.m. then at what time they will ring together?.1. 12 noon2. 1 p.m.3. 11 a.m.4. 2 p.m.

Answer» Correct Answer - Option 2 : 1 p.m.

Given:

4 bells beep at an interval of 4, 12, 20, and 25.minutes.

Beep together at 8 a.m.

Concept used:

Using LCM method

Calculation:

4 = 2 × 2

12 = 2 × 2 × 3

20 = 2 × 2 × 5

25 = 5 × 5

LCM of 4, 12, 20 and 25 = 2 × 2 × 3 × 5 × 5

⇒ 300 minutes 

⇒ 5 hour

So, 8 a.m. + 5 hour = 13 p.m. = 1 p.m.

∴ They will beep together again at 1 p.m.

15.

Three bells ring at intervals of 4, 7 and 14 minutes. All three rang at 6 AM. When will they ring together again?(a) 6:07 AM(b) 6:14 AM(c) 6:28 AM(d) 6:25 AM

Answer»

Correct answer is: (c) 6:28 AM

LCM 0f 4,7,14=28

Bells will they ring together again at 6:28 AM

16.

Three bells ring at the interval of 7, 10 and 12 seconds. They start ringing simultaneously at 2:00 pm. At what time will they ring again simultaneously?1. 3 : 10 pm2. 3 : 30 pm3. 2 : 07 pm4. 2 : 30 pm

Answer» Correct Answer - Option 3 : 2 : 07 pm

Given:

Three bells ring at the interval of 7, 10 and 12 seconds and they ring simultaneously at 2:00 pm.

Calculation:

Three bells rings at the interval of 7, 10 and 12 seconds and to calculate the time at which the bells ring again simultaneous we take the LCM of the given time intervals.

LCM of (7, 10 and 12) = 2 × 2 × 3 × 5 × 7 = 420 seconds = 7 minutes

∴ Three bells ring again after 7 minutes.

So, the time at which three bells ring again simultaneously = 2:00 pm + 7 min = 2:07 pm.

17.

The greatest number which on dividing 1657 and 2037 leaves remainders 6 and 5 respectively, is:1. 1232. 1273. 2354. 305

Answer» Correct Answer - Option 2 : 127

Concept used:

HCF = Highest common factor 

The greatest number which divides each of the two or more numbers is called HCF or Highest Common Factor.

Calculations:

Required number = H.C.F. of (1657 - 6) and (2037 - 5)

H.C.F. of 1651 and 2032

1651 = 13 × 127 

2032 = 4 × 4 × 127

HCF of 1651 and 2032 = 127

∴ The greatest number which on dividing 1657 and 2037 leaves remainders 6 and 5 respectively, is 127.

18.

The sum of the greatest 4‐digit number and the smallest 3‐digit number is:‐1. 70002. 98993. 100994. 10999

Answer» Correct Answer - Option 3 : 10099

The greatest 4 digit number is 9999,

Smallest 3 digit number is 100

Sum of 9999 + 100 = 10099

19.

The smallest three-digit prime number is1. 1012. 1033. 1074. None of these

Answer» Correct Answer - Option 1 : 101

Concept:

 prime numbers are number that has only 2 factors: 1 and themselves. 

Calculation:

Smallest 3 digit number is 100 which is not a prime number.

101 is the next number which is divisible by 1 and 101

∴ 101 is the smallest prime number 

 

 

 

 

 

20.

What will be the remainder when the smallest two digit prime number is divisible by 5.1. 32. 43. 14. 8

Answer» Correct Answer - Option 3 : 1

Given

Smallest two-digit prime number = 11

Concept

Remainder theorem

Dividend = Divisor × quotient + remainder 

A prime number is a number that is divisible by 1 and by itself only. For example 2,3, 5, etc.

Calculations

11 = 5 × 2 + Remainder

11 - 10 = Remainder

1 = Remainder

21.

The difference between the smallest three-digit prime number and the greatest two-digit prime number is1. 22. 33. 44. None of the above

Answer» Correct Answer - Option 3 : 4

Concept:

Prime numbers are whole numbers greater than 1, that have only two factors i.e., 1 and the number itself

Calculation

Smallest three-digit prime number = 101

Greatest two-digit prime number = 97

Their difference = 101 - 97 = 4

22.

\(\frac{{{{\left( {598 + 479} \right)}^2} - {{\left( {598 - 479} \right)}^2}}}{{598 \times 479}} = \;?\)1. 42. 103. 1324. 85. None of the above/More than one of the above

Answer» Correct Answer - Option 1 : 4

Formulae Used:

(a + b)2 = a2 + 2ab + b2

(a - b)2 = a2 - 2ab + b2

Calculation:

Let us consider a = 598, and b = 479

So, the numerator = a2 + 2ab + b2 - (a2 - 2ab + b2) = 4ab

and the denominator = a × b = ab

∴ ? = 4ab/ab = 4

23.

If 2(422 + 422)(322 + 322 + 322) = 12(p + 3) then, find the value of p/5?1. 32. 23. 44. 5

Answer» Correct Answer - Option 3 : 4

GIVEN:

2(422 + 422)(322 + 322 + 322) = 12(p + 3)

CALCULATIOON :

2(422 + 422)(322 + 322 + 322) = 12(p + 3)

⇒ 2 × 2 × 422 × 3 × 322 = 12(p + 3)

⇒ 423 × 323 = 12(p + 3)

⇒ 1223 = 12(p + 3)

On comparing –

⇒ 23 = p + 3

⇒ p = 20

According to question –

⇒ p/5 = 20/5 = 4

24.

The value of the following is given by 100 (kilo ampere ) x ( micro ampere ) 100 milli ampere x 10 ampere  (A) 0.001 A (B) 0.1 A (C) 1 A (D) 10A

Answer»

The value of the following is given by 100 (kilo ampere) x ( micro ampere) 100 milli ampere x 10 ampere  0.1 A.

25.

एक 6 फ़ीट लम्बे आदमी झंडे छाया 4 फ़ीट लम्बी है । उसी समय एक झंडे की छाया 50 फ़ीट लम्बी है । झंडे की ऊंचाई ज्ञात करे ।A. 80ftB. 75ftC. 60ftD. 70ft

Answer» Correct Answer - B
`{:("Height","Shadow"),("6ft","4ft"),(3,2):}`
So height of pole will be in same ratio.
`=50xx3/2=75 ft`
26.

The ratio of three numbers is 2 : 3 : 6 and their HCF is 45. Find the sum of these numbers.A. 405B. 455C. 495D. 5251. B2. A3. C4. D

Answer» Correct Answer - Option 3 : C

Given:

Ratio of three numbers = 2 : 3 : 6

HCF = 45

Calculation: 

let the number be 2x, 3x, 6x

HCF is the common factor for all numbers

adding all the number = 2x + 3x + 6x = 11x 

∵ both the x and HCF is common in all the number

Substituting the value of HCF in x 

Sum of the three numbesr = 11 × 45 = 495

∴ The sum of the three number is 495

27.

The HCF and LCM of two numbers are 13 and 455 respectively. If one of the number is 65, then other number is:1. 912. 1043. 784. 117

Answer» Correct Answer - Option 1 : 91

Given:

HCF = 13

LCM = 455

One number = 65

Concept used:

HCF × LCM = Product of the numbers

Calculation:

Let x be the second number.

13 × 455 = 65 × x

⇒ x = 13 × 455/65 = 91

The second number is 91.

28.

Data arranged in ascending or descending order of magnitude is called: (a) Ungrouped data (b) Grouped data (c) Discrete frequency distribution (d) Arrayed data

Answer»

(d) Arrayed data

29.

AB is a current carrying conductor in the plane of the paper as shown in Figure 13.7. What are the directions of magnetic fields produced by it at points P and Q? Given r1 > r2, where will the strength of the magnetic field be larger?

Answer» Into the plane of paper at P and out of it at Q. The strength of the magnetic field is larger at the point located closer i.e. at Q.
30.

Directions: Each of the questions given below consists of a question and 2 statements numbered I and II. You have to decide whether the data is sufficient to answer the question. Read both Statements carefully and then answer the questions.A surveyor draws three parallel straight lines on a paper for a land survey. Two points A1 and A2 are marked on the first straight line points A3 and A4 are marked on the second straight line and points A5 and A6 are marked on the third line. These six points can move to any position on their respective straight line.Statement I. The maximum number of triangles that can be formed by joining these points is 20.Statement II. The minimum number of triangles that can be formed by joining these points is 3.1. The data in statement I alone is sufficient to answer the question, while the data in statement II alone is not sufficient to answer the question.2. The data in statement II alone is sufficient to answer the question, while the data in statement I alone is not sufficient to answer the question.3. The data in statement I alone or in statement II alone is sufficient to answer the question.4. The data in both statements I and II are not sufficient to answer the question.5. The data in both statements I and II together are necessary to answer the question.

Answer» Correct Answer - Option 1 : The data in statement I alone is sufficient to answer the question, while the data in statement II alone is not sufficient to answer the question.

Given:

3 parallel straight lines

6 points = A1, A2, A3, A4, A5, A6

Calculation:

The maximum triangles would be in case of all 6 points are non-collinear. In such a case the number of triangles is 6C3

⇒ (6 × 5 × 4) / (1 × 2 × 3)

⇒ 20

Statement I is correct.

In another case, if the surveyor takes the position that A1 and A2 coincide on the 1st line, similarly A3 and A4 coincide on the 2nd line and A5 and A6 coincide on the 3rd line. In such a case there will be 0 triangles.

∴ Statement II is incorrect.
31.

Directions: Each of the questions given below consists of a question and 2 statements numbered I and II. You have to decide whether the data is sufficient to answer the question. Read both Statements carefully and then answer the questions.What is the marked price of the scarf?Statement I. A shopkeeper purchases 2 scarfs for Rs. 2200 and earns Rs. 55 per scarf after giving a 23% discount.Statement II. A shopkeeper marks the price 36% more than the cost price and earns Rs. 200 after giving some discount.1. The data in statement I alone is sufficient to answer the question, while the data in statement II alone is not sufficient to answer the question.2. The data in statement II alone is sufficient to answer the question, while the data in statement I alone is not sufficient to answer the question.3. The data in statement I alone or in statement II alone is sufficient to answer the question.4. The data in both statements I and II are not sufficient to answer the question.5. The data in both statements I and II together are necessary to answer the question.

Answer» Correct Answer - Option 1 : The data in statement I alone is sufficient to answer the question, while the data in statement II alone is not sufficient to answer the question.

Given:

For Statement I:

Cost price of 2 scarfs = Rs. 2200

Earns = Rs. 55 per scarf

Discount = 23%

For Statement II:

Marks up the C.P = 36%

Earns = Rs. 200

Calculation:

For Statement I:

The cost price of a shirt = Rs. 1100

Selling Price = 1100 + 55

⇒ Rs. 1155

Marked Price = 1155 / 77 × 100

⇒ Rs. 1500

Statement I is sufficient to answer the question.

For Statement II:

Let the cost price be x.

Marked Price = x × 136%

⇒ 1.36x%

Selling Price = x + 200

Statement II is not sufficient to answer the question.
32.

In LR circuit (shown in figure), current is lagging by `pi/3` in phase with applied voltage, then select correct alternative: A. `L=10/(sqrt(3)pi)H,i=10A`B. `L=10/(pi)H,i=5A`C. `L=10/(sqrt(3)pi) H,i=5A`D. `L=(sqrt(3))/(10 pi)H,i=5A`

Answer» `(X_(L))/R=sqrt(3)rArr x_(L)=Rsqrt(3)`
`i=100/(sqrt((10sqrt(3))^(2)+(10)^(2)))=5A`
`L=(10sqrt(3))/(100pi)=(sqrt(3))/(10 pi) H`
33.

There are two statements following one of the questions below. Analyze and decide whether the questions can be answered with the given statements.Question: Is X an integer number?Statement I: 2X + 3 = 7Statement II: 3X + 4Y - 11 = 01. Statements I and II are required simultaneously2. Statements I and II together are not sufficient3. Statement II alone is sufficient4. Statement I alone is sufficient

Answer» Correct Answer - Option 4 : Statement I alone is sufficient

Statement I:

2X + 3 = 7 

2X = 7 - 3  

2X = 4 

X = 4 / 2

X = 2

The the value of X is known. 

So, statement 1 alone is sufficient to answer the question.

Statement II: 

3X + 4Y - 11 = 0 

Here the value of X and Y are not found.

So, statement 2 alone is not sufficient.

Thus X = 2, X is an integer number.

Hence, the correct answer is "Statement I alone is sufficient".

34.

Pyroligneous acid (one of the fraction of destructive distillation of wood), does not containA. Stearic acidB. Acetic acidC. MethanolD. Acetone

Answer» Correct Answer - A
Pyroligneous aicd does not contain stearic acid.
35.

How many are paramagnetic speciesNa2O, KO2, N2O, NO2, SO2, ClO2, Cl2O

Answer»

Diamagnetic ⇒ Na2O, N2O, SO2, Cl2O

Paramagnetic ⇒ KO2, NO2, ClO2

36.

On heating ammonium dichromate and barium azide separately, we getA. `N_(2)` with ammonium dichromate and NO with barium azideB. `N_(2)O` with ammonium dichromate and `NO_(2)` with barium azideC. `N_(2)O` with ammonium dichromate and NO with barium azideD. `N_(2)` in both cases

Answer» Correct Answer - D
`(NH_(4))_(2) Cr_(2) O_(7) overset(Delta)rarr N_(2) + Cr_(2)O_(7) + H_(2)O`
`Ba (N_(3))_(2) overset(Delta)rarr Ba + N_(2)`
37.

Calculate the standard enthalpy of formation of `CH_(3)OH(l)` from the following data: `CH_(3)OH(l)+3/2O_(2)(g) rarr CO_(2)(g)+2H_(2)O(l), …(i), Delta_(r)H_(1)^(Θ)=-726 kJ mol^(-1)` `C(g)+O_(2)(g) rarr CO_(2)(g), …(ii), Delta_(c )H_(2)^(Θ)=-393 kJ mol^(-1)` `H_(2)(g)+1/2O_(2)(g) rarr H_(2)O(l), ...(iii), Delta_(f)H_(3)^(Θ)=-286 kJ mol^(-1)`

Answer» `C(s)+2H_(2)(g)+1/2O_(2)(g)rarr CH_(3)OH(l), Delta_(f)H^(Θ)=`?
Equation (ii) `+2xx"Equation"` (iii) -Equation (i) gives the required equation with
`DeltaH=-393+2(-286)-(-726)kJ "mol"^(-1)=-239 kJ "mol"^(-1)`
38.

Assertion`:-`Internal energy of a real gas may change during expansion at const. temperature. Reason`:-` Internal energy of a real gas ia function of `T` & `P`.A. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion.B. If both Assertion & Reason are True but Reason is not a correct explanation of the Assertiion.C. If Assertion is True but the Reason is False.D. If both Assertion & Reason are False

Answer» Correct Answer - A
39.

`DeltaU^(@)` of combustoin of methane is `-XKJ mol ^(-1)` The value of `DeltaH^(@)` is :-A. `-X-596R`B. `-X+596R`C. `X+596R`D. `X-596R`

Answer» Correct Answer - A
`CH_(4)(g)+2O(g)toCO_(2)(g)+2H_(2)(g)+2H_(2)O(l)`
`DeltaH^(@)=DeltaH^(@)=DeltaU^(@)+Deltan_(g)RT`
`DeltaH^(@)=-x+(-2)Rxx298`
`DeltaH^(@)=-x-596R`
40.

Assertion`:-` For the combustion of methane `DeltaHltDeltaU` at `125^(@)` Reason`:-` For combustion `DeltaH` is always less than `DeltaU`A. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion.B. If both Assertion & Reason are True but Reason is not a correct explanation of the Assertiion.C. If Assertion is True but the Reason is False.D. If both Assertion & Reason are False

Answer» Correct Answer - D
41.

`DeltaU^(Θ)` of combustion of methane is `-XkJ mol^(-1)`. The value of `DeltaH^(Θ)` isA. `=DeltaU^(Θ)`B. `gt DeltaU^(Θ)`C. `lt DeltaU^(Θ)`D. zero

Answer» Correct Answer - c
The balance equation for combustion of methane with be
`CH_(4)(g)+2O_(2)(g) rarr CO_(2)(g)+2H_(2)O(l)`
Thus, `Deltan_(g)=(n_(p)-n_(r))_(g)=1-3=-2`
`DeltaH^(Θ)=DeltaU^(Θ)+Deltan_(g)RT=-X-2 RT`
Thus, `DeltaH^(Θ) lt DeltaU^(Θ)`
42.

The enthalpy of combustion of methane, graphite and dihydrogen at `298 K` are, `-890.3 kJ mol^(-1) -393.5 kJ mol^(-1)`, and `-285.8 kJ mol^(-1)` respectively. Enthapy of formation of `CH_(4)(g)` will beA. `-74.8 kJ mol^(-1)`B. `-52.27 kJ mol^(-1)`C. `+74.8 kJ mol^(-1)`D. `+52.26 kJ mol^(-1)`

Answer» Correct Answer - a
Given:
a. `CH_(4)(g)+2O_(2)(g) rarr CO_(2)(g)+2H_(2)O(l), DeltaH=-890.3 kJ mol^(-1)`
b. `C(s)+O_(2)(g) rarr CO_(2)(g), DeltaH=-393.5 kJ mol^(-1)`
c. `H_(2)(g)+1/2 O_(2)(g)rarr H_(2)O(l), DeltaH=-285.8 kJ mol^(-1)`
Aim: `C(s)+2H_(2)(g) rarr CH_(4)(g), DeltaH=?`
Equation `(b)+2xx` Equation (c ) -Equation (a) gives the required equation with `DeltaH=-393.5+2(-285.8)-(-890.3) kJ mol^(-1)`
`=-74.8 kJ mol^(-1)`
43.

Calculate the enthalpy change for the reaction H2 (g) + Br2 (g) 2HBr (g) Given that the bond enthalpies of H–H, Br–Br, H–Br are 435, 192 and 364 kJ mol–1 respectively.

Answer»

Δr H = ∑B.E. (Reactants) – ∑B.E. (Products) 

= [B.E. (H2) + B.E. (Br2 )] – 2 B.E. (HBr) 

= 435 + 192 – 2 × 364 = – 101 kJ.

44.

For a spontaneous chemical process, the free energy change is(a) positive (b) negative (c) either positive or negative (d) zero

Answer»

(b) negative 

45.

In which of the following cases, the reaction is spontaneous at all temperatures ? (a) ΔH > 0, ΔS > 0 (b) ΔH < 0, ΔS > 0 (c) ΔH < 0, ΔS < 0 (d) ΔH > 0, ΔS < 0

Answer»

(b) ΔH < 0, ΔS > 0 

46.

Gibb’s free energy G, enthalpy H and entropy S are related to one another by (a) G = H + TS (b) G = H – TS (c) G – TS = H (d) S = H – G

Answer»

(b) G = H – TS 

47.

The enthalpy and entropy change for a chemical reaction are – 2.5 × 103 cal and 7.4 cal deg–1 respectively. The reaction at 298 K will be (a) spontaneous (b) reversible (c) irreversible (d) non-spontaneous. 

Answer»

(a) spontaneous 

48.

Draw the structures of optical isomers of: (i). `[Cr(C_2O_4)_3]^(3-)` (ii). `[PtCl_2(en)_2]^(2+)` (iii). `[Cr(NH_3)_2Cl_2(en)]^(o+)`

Answer» `[CoCl_2(en)_2]^(o+)` is of `[M(AA)_2b_2]^(n+-)` type
(ii). `[Co(NH_3)Cl(en)_2]^(2+)` is of `[M(AA)_2ab]^(n+-)` type.
(iii). `[Co(NH_3)_2Cl_2(en)]^(o+)` is of `[M(AA)a_2b_2]^(n+-)` type.
49.

Write all the geometrical isomers of `[Pt(NH_3)(Br)(Cl)(py)]` and how many of these will exhibit optical isomers?

Answer» `[Pt(NH_3)(Br)(Cl)(py)]` is of `[Mabcd]^(n+-)` type. It shows geometrical isomers.
50.

The most suitable reagent for the conversion of Benzyl alcohol to benzoic acid isA. acidified`KMnO_4`B. PCCC. both of theseD. none of these

Answer» Correct Answer - A