Explore topic-wise InterviewSolutions in Current Affairs.

[Hint : (i) Due to presence of lone pair of electron on N in NO₂^-
(ii) Bi^-H bond dissociation enthalpy is least and releases hydrogen mosteasily.
(iii) NH₃ is stronger Lewis base than PH₃.]

Chlorobenzene is less reactive towards nucleophilic substitution reactions due to the following reasons: 

(a) Partial double bond character of C- Cl bond 

(b) sp² hybridisation of carbon

(b) 2KMnO₄ + 16HCl → 2KCl + 2MnCl₂ + 8H₂O + 5Cl₂

(d) He, Ne, Ar, Kr

(c) XeF₆ + 3H₂O → XeO₃ + 6HF 

Complete hydrolysis of XeF₆ gives XeO₃ (an explosive).

Fluorine is a much stronger oxidizing agent than chlorine. The oxidizing power depends on three factors.
1. Bond dissociation energy
2. Electron gain enthalpy
3. Hydration enthalpy
The electron gain enthalpy of chlorine is more negative than that of fluorine. However, the bond dissociation energy of fluorine is much lesser than that of chlorine. Also, because of its small size, the hydration energy of fluorine is much higher than that of chlorine. Therefore, the latter two factors more than compensate for the less negative electron gain  enthalpy of fluorine. Thus, fluorine is a much stronger oxidizing agent than chlorine.

Anomalous behaviour of fluorine

(i)    It forms only one oxoacid as compared to other halogens that form a number of oxoacids.
(ii)    Ionisation enthalpy, electronegativity, and electrode potential of fluorine are much higher than expected.

When an aqueous solution of borax is acidified with HCl boric acid is formed
Na₂B₄O₇ + 2HCl + 5H₂O → 2NaCl + 4H₃BO₃ (BORIC ACID)
Boric acid is not a proticacid it does not give H⁺ ion accepts a pair of electrons
and acts as a Lewis acid.

Human body contains radioactive elements that are Naturally occurring potassium-40, carbon-14, uranium, and thorium are present in every human body.

Our bodies are naturally radioactive, because we eat, drink, and breathe radioactive substances that are naturally present in the environment. These substances are absorbed by our bodies, into our tissues, organs, and bones, and are constantly replenished by ingestion and inhalation.

Correct option is  (c) Amytal

Derivatives of barbituric acid viz, veronal, amytal, nembutal, luminal and seconal constitute an important class of tranquilizers. These are hypnotic.

(A) Calamine  ⇒  ZnCO₃

(B) Galena  ⇒ Pbs

(C) Sphalerite ⇒ ZnS

(D) Siderite ⇒ FeCO₃

Answer: 5.90 V

its (x sin2y) in the question 

(x + 2y)\(\frac{dy}{dx}=x\) 

⇒ \(\frac{dy}{dx} = \frac x{x+2y} = \cfrac1{1+\frac{2y}x}\) 

Let y/x = v ⇒ y = vx

⇒ \(\frac{dy}{dx} = v+x\frac{dv}{dx}\)

∴ v + \(x\frac{dv}{dx}\) = \(\frac1{1+2v}\) 

⇒ \(x\frac{dv}{dx}\) = \(\frac1{1+2v}-v\) = \(\frac{1-v-2v^2}{1+2v}\) 

⇒ \(\frac{1+2v}{1-v-2v^2}dv=\frac{dx}x\) 

⇒ \(\int\frac12(\frac{2+4v}{1-v-2v^2})dv=\int\frac{dx}x\)

⇒ \(\int\frac12(\frac{1+4v}{1-v-2v^2}+\frac1{1-v-2v^2})dv=\int\frac{dx}x\)

⇒ -\(\frac12\)log|1 - v - 2v²|  - \(\frac14\int\frac1{(v+\frac14)^2-(\frac34)^2} = log x+c\) 

⇒ -\(\frac12\)log|1 - v - 2v²| - \(\frac14\times\frac1{2\times3/4}\) log\(|\frac{v+1/4-3/4}{v+1/4+3/4}|=\log x + c\)

⇒ -\(\frac12\)log|1 - v - 2v²| - \(\frac16\)log|\(\frac{uv-2}{uv+4}\)| = log x + c 

⇒ -\(\frac12\)log(1 - v - 2v²) - \(\frac16\) log|\(\frac{2v-1}{2v+2}\)| = log x + c

⇒ -\(\frac12\)log(1 - yx - 2y²/x²) - 1/6 log|\(\frac{2y-x}{2y+2x}\)|  = log x + c

\((\because \forall=\frac yx)\)

which is solution of given homogenous differential equation.

Merits: 

(i) The specificity of a catalyst 

(ii) The increase in the rate of the reaction with increase in the concentration of catalyst. 

Limitations: 

(i) This theory fails to explain the action of catalytic poison and promoters.

(ii) This theory is unable to explain the mechanism of heterogeneous catalysed reactions.

Isotropy: 

1. Isotropy means uniformity in all directions.

2. Isotropy means having identical values of physical properties such as refractive index, electrical conductance in all directions. 

3. Isotropy is the property of amorphous solids. 

Anisotropy : 

1. Anisotropy means non-uniformity in all directions. 

2. Anisotropy is the property which depends on the direction of measurement. They show different values of physical properties when measured along different directions. 

3. Anisotropy is the properly of crystalline solids.

A force is a push or pull upon an object resulting from the object's interaction with another object. 

Some examples of forces are :

Frictional Force

Tension Force

Normal Force

Gravitational Force

Electrical Force

Magnetic Force

Lowest possible temperature in fahrenheit  −459.67 °F

Lowest possible temperature in Rankine 0R

A volume of 1 gal equals 231 in³, the density is 46.8 lbm / ft³, 

so we get

m = pV = 46.8lbm / ft³ x 1 x (231 / 12³) ft³ = 6.256 lbm

A more accurate value is p = 848 lbm / ft³.

For the helium that density is 10.08 x 10^-3 lbm / ft³ 

so we get

m = pV = 10.08 x 10^-3 lbm / ft³ x 1 x (231 / 12³) ft³ = 0.00135 lbm

Answer (b) two

Ethyne molecule has one single covalent bond and two pi covalent bonds.

Given:

The ages ratio of father and child = 9: 1

Their ages sum = 40

Calculations:

Let the ages of the father and child be 9x and x

According to the questions,

⇒ 9x + x = 40

⇒ 10x = 40

⇒ x = 4

The Ages of the father and the child are 36 years and 4 years

The Ages of the father and the child 8 years later are 44 years and 12 years

The required ratio = 44 ∶ 12 = 11 ∶ 3

∴ The required ratio is 11 ∶ 3  

Given:

Raj’s age = 50 years

Neha’s age = 25 years

Calculations:

Let after x years Raj’s age and Neha’s be 50 + x, 25 + x

According to the question,

⇒ (50 + x)/(25 + x) = 6/5

⇒ (250 + 5x) = (150 + 6x) 

⇒ x = 100

∴ After 100 years the ratio of Raj and Neha’s age become 6 ∶ 5

Your question option is likely to be Yb³⁺, Pm³⁺ ,Ce³⁺, La³⁺

Yb³⁺  has smallest ionic radius because atomic and ionic radii of lanthanide decreses from La to Lu

Thus order of radii is  

Yb³⁺ < Pm³⁺ < Ce³⁺ < La³⁺

Given:

The sum of ages 8 children born at the intervals of 8 years each is = 80

Calculation

Let the ages of children be x, (x + 8), (x + 16), (x + 24) years

According to the question,

x + (x + 8) + (x + 16) + (x + 24) = 80

⇒ 4x = 80 – 48

⇒ 4x = 32

⇒ x = 8

∴ Age of the youngest child is 8 years

Concept used:

Number of all permutations of n things = n!

Calculation:

The word ANUBHAW contain 7 letters but the letter A appears two times

⇒ No. of way = 7!/2!

⇒ (7 × 6 × 5 × 4 × 3 × 2!)/2!

⇒ 7 × 6 × 5 × 4 × 3

⇒ 2520

∴ The word ANUBHAW can be rearranged in 2520 ways

Concept used:

Number of all the permutations of n things = n!

Calculation:

The given word is ANUBHAW in this word we take all consonants as one letter

AUANBHW  in this word NBHW treat as one letter

This arrangement has 4 letters of which A appears two times 

⇒ Number of ways = 4!/2!

⇒ (4 × 3 × 2!)/2!

⇒ 12

Now, four consonants can be arranged among them as 4! = 4 × 3 × 2× 1

⇒ 24 ways 

Required number of ways = 12 × 24

⇒ 288

∴ The required number of ways is 288

GIVEN:

The ratio of successful to unsuccessful candidates is 11x : 8x

Total number of applied candidates = 19x

CALCULATION:

(19x + 80)/(8x - 30) = 12/5

⇒ 95x + 400 = 96x - 360

⇒ x = 760

Total applicants = 19 × 760 = 14,440 

∴ The correct answer is 14,440

GIVEN:

⇒ Word = “NCISORTP”

⇒ Total Alphabets = 8

CALCULATION:

Possible ways:-

⇒  (P,R,T,N,C,S)6 x 7 x 6 x 5 x 4 x 3 x 2 x 1

⇒ Possible ways = 30240