eSaral - JEE | NEET | Class 8-10 Exam Prep App

Explain why BeH2 molecule has a zero dipole moment although the Be–H bonds are polar.

Question: Explain why BeH2molecule has a zero dipole moment although the BeH bonds are polar. Solution: The Lewis structure for BeH2is as follows: There is no lone pair at the central atom (Be) and there are two bond pairs. Hence, BeH2is of the type AB2. It has a linear structure. Dipole moments of each HBe bond are equal and are in opposite directions. Therefore, they nullify each other. Hence, BeH2molecule has zero dipole moment....

What is Tidal volume? Find out the Tidal volume (approximate value) for a healthy human in an hour.

Question: What is Tidal volume? Find out the Tidal volume (approximate value) for a healthy human in an hour. Solution: Tidal volume is the volume of air inspired or expired during normal respiration. It is about 6000 to 8000 mL of air per minute. The hourly tidal volume for a healthy human can be calculated as: Tidal volume = 6000 to 8000 mL/minute Tidal volume in an hour = 6000 to 8000 mL (60 min) = 3.6 105mL to 4.8 105mL Therefore, the hourly tidal volume for a healthy human is approximately ...

Apart from tetrahedral geometry, another possible geometry for CH4 is square planar

Question: Apart from tetrahedral geometry, another possible geometry for CH4is square planar with the four H atoms at the corners of the square and the C atom at its centre. Explain why CH4is not square planar? Solution: Electronic configuration of carbon atom: ${ }_{6} \mathrm{C} \cdot 1 s^{2} 2 s^{2} 2 p^{2}$ In the excited state, the orbital picture of carbon can be represented as: Hence, carbon atom undergoessp3hybridization in CH4molecule and takes a tetrahedral shape. For a square planar s...

Distinguish between

Question: Distinguish between (a) IRV and ERV (b) Inspiratory capacity and Expiratory capacity (c) Vital capacity and Total lung capacity Solution:...

What universal set (s) would you propose for each of the following:

Question: What universal set (s) would you propose for each of the following: (i)The set of right triangles (ii)The set of isosceles triangles Solution: (i)For the set of right triangles, the universal set can be the set of triangles or the set of polygons. (ii)For the set of isosceles triangles, the universal set can be the set of triangles or the set of polygons or the set of two-dimensional figures....

Write the following intervals in set-builder form:

Question: Write the following intervals in set-builder form: (i)(3, 0) (ii)[6, 12] (iii)(6, 12] (iv)[23, 5) Solution: (i)(3, 0) = {x:x R, 3 x 0} (ii)[6, 12] = {x:x R, 6 x 12} (iii)(6, 12] ={x:x R, 6 x 12} (iv)[23, 5) = {x:x R, 23 x 5}...

Write the following as intervals:

Question: Write the following as intervals: (i){x:x R, 4 x 6} (ii){x:x R, 12 x 10} (iii){x:x R, 0 x 7} (iv){x:x R, 3 x 4} Solution: (i){x:x R, 4 x 6} = (4, 6] (ii){x:x R, 12 x 10} = (12, 10) (iii){x:x R, 0 x 7} = [0, 7) (iv){x:x R, 3 x 4} = [3, 4]...

The skeletal structure of CH3COOH as shown below is correct, but some of the bonds are shown incorrectly.

Question: The skeletal structure of CH3COOH as shown below is correct, but some of the bonds are shown incorrectly. Write the correct Lewis structure for acetic acid. Solution: The correct Lewis structure for acetic acid is as follows:...

How many elements has P(A), if A = Φ?

Question: How many elements has P(A), if A = Φ? Solution: We know that if $A$ is a set with $m$ elements i.e., $n(A)=m$, then $n[P(A)]=2^{m}$. If $A=\Phi$, then $n(A)=0 .$ $\therefore n[\mathrm{P}(\mathrm{A})]=2^{0}=1$ Hence, $P(A)$ has one element....

Write down all the subsets of the following sets:

Question: Write down all the subsets of the following sets: (i){a} (ii){a,b} (iii){1, 2, 3} (iv)Φ Solution: (i)The subsets of {a} are Φ and {a}. (ii)The subsets of {a,b} areΦ, {a}, {b}, and {a,b}. (iii)The subsets of {1, 2, 3} areΦ, {1}, {2}, {3}, {1, 2}, {2, 3}, {1, 3}, and {1, 2, 3} (iv)The only subset of Φ isΦ....

Have you heard about hypoxia? Try to gather information about it, and discuss with your friends.

Question: Have you heard about hypoxia? Try to gather information about it, and discuss with your friends. Solution: Hypoxia is a condition characterised by an inadequate or decreased supply of oxygen to the lungs. It is caused by several extrinsic factors such as reduction in pO2, inadequate oxygen, etc. The different types of hypoxia are discussed below. Hypoxemic hypoxia In this condition, there is a reduction in the oxygen content of blood as a result of the low partial pressure of oxygen in...

Arrange the bonds in order of increasing ionic character in the molecules: LiF, K2O, N2, SO2 and ClF3.

Question: Arrange the bonds in order of increasing ionic character in the molecules: LiF,K2O, N2, SO2and ClF3. Solution: The ionic character in a molecule is dependent upon the electronegativity difference between the constituting atoms. The greater the difference, the greater will be the ionic character of the molecule. On this basis, the order of increasing ionic character in the given molecules is N2 SO2 ClF3 K2O LiF....

Let A= {1, 2, {3, 4,}, 5}. Which of the following statements are incorrect and why?

Question: Let A= {1, 2, {3, 4,}, 5}. Which of the following statements are incorrect and why? (i){3, 4} A (ii){3, 4}} A (iii){{3, 4}} A (iv)1 A (v)1 A (vi){1, 2, 5} A (vii){1, 2, 5} A (viii){1, 2, 3} A (ix)Φ A (x)Φ A (xi){Φ} A Solution: A = {1, 2, {3, 4}, 5} (i)The statement {3, 4} A is incorrect because 3 {3, 4}; however, 3A. (ii)The statement {3, 4} A is correct because {3, 4} is an element of A. (iii)The statement {{3, 4}} A is correct because {3, 4} {{3, 4}} and {3, 4} A. (iv)The statement 1...

Explain with the help of suitable example polar covalent bond.

Question: Explain with the help of suitable example polar covalent bond. Solution: When two dissimilar atoms having different electronegativities combine to form a covalent bond, the bond pair of electrons is not shared equally. The bond pair shifts towards the nucleus of the atom having greater electronegativity. As a result, electron distribution gets distorted and the electron cloud is displaced towards the electronegative atom. As a result, the electronegative atom becomes slightly negativel...

Examine whether the following statements are true or false:

Question: Examine whether the following statements are true or false: Examine whether the following statements are true or false: (i){a,b} {b,c,a} (ii){a,e} {x:xis a vowel in the English alphabet} (iii){1, 2, 3} {1, 3, 5} (iv){a} {a.b,c} (v){a} (a,b,c) (vi){x:xis an even natural number less than 6} {x:xis a natural number which divides 36} Solution: (i)False. Each element of {a,b} is also an element of {b,c,a}. (ii)True.a,eare two vowels of the English alphabet. (iii)False. 2{1, 2, 3}; however, ...

Define electronegativity. How does it differ from electron gain enthalpy?

Question: Define electronegativity. How does it differ from electron gain enthalpy? Solution: Electronegativity is the ability of an atom in a chemical compound to attract a bond pair of electrons towards itself. Electronegativity of any given element is not constant. It varies according to the element to which it is bound. It is not a measurable quantity. It is only a relative number. On the other hand, electron gain enthalpy is the enthalpy change that takes place when an electron is added to ...

Define oxygen dissociation curve. Can you suggest any reason for its sigmoidal pattern?

Question: Define oxygen dissociation curve. Can you suggest any reason for its sigmoidal pattern? Solution: The oxygen dissociation curve is a graph showing the percentage saturation of oxyhaemoglobin at various partial pressures of oxygen. The curve shows the equilibrium of oxyhaemoglobin and haemoglobin at various partial pressures. In the lungs, the partial pressure of oxygen is high. Hence, haemoglobin binds to oxygen and forms oxyhaemoglobin. Tissues have a low oxygen concentration. Therefo...

Make correct statements by filling in the symbols ⊂ or ⊄ in the blank spaces:

Question: Make correct statements by filling in the symbols or in the blank spaces: (i){2, 3, 4} {1, 2, 3, 4, 5} (ii){a,b,c} {b,c,d} (iii){x:xis a student of Class XI of your school} {x:xstudent of your school} (iv){x:xis a circle in the plane} {x:xis a circle in the same plane with radius 1 unit} (v){x:xis a triangle in a plane}{x:xis a rectangle in the plane} (vi){x:xis an equilateral triangle in a plane} {x:xis a triangle in the same plane} (vii){x:xis an even natural number} {x:xis an intege...

Write the significance/applications of dipole moment

Question: Write the significance/applications of dipole moment Solution: In heteronuclear molecules, polarization arises due to a difference in the electronegativities of the constituents of atoms. As a result, one end of the molecule acquires a positive charge while the other end becomes negative. Hence, a molecule is said to possess a dipole. The product of the magnitude of the charge and the distance between the centres of positive-negative charges is called the dipole moment () of the molecu...

From the sets given below, select equal sets:

Question: From the sets given below, select equal sets: A = {2, 4, 8, 12}, B = {1, 2, 3, 4}, C = {4, 8, 12, 14}, D = {3, 1, 4, 2} E = {1, 1}, F = {0,a}, G = {1, 1}, H = {0, 1} Solution: A = {2, 4, 8, 12}; B = {1, 2, 3, 4}; C = {4, 8, 12, 14} D = {3, 1, 4, 2}; E = {1, 1}; F = {0,a} G = {1, 1}; A = {0, 1} It can be seen that 8 A, 8 B, 8 D, 8 E, 8 F, 8 G, 8 H ⇒ A B, A D, A E, A F, A G, A H Also, 2 A, 2 C A C 3 B, 3 C, 3 E, 3 F, 3 G, 3 H B C, B E, B F, B G, B H 12 C, 12 D, 12 E, 12 F, 12 G, 12 H C D...

What is the site of gaseous exchange in an insect?

Question: What is the site of gaseous exchange in an insect? Solution: In insects, gaseous exchange occurs through a network of tubes collectively known as the tracheal system. The small openings on the sides of an insects body are known as spiracles. Oxygen-rich air enters through the spiracles. The spiracles are connected to the network of tubes. From the spiracles, oxygen enters the tracheae. From here, oxygen diffuses into the cells of the body. The movement of carbon dioxide follows the rev...

Are the following pair of sets equal? Give reasons.

Question: Are the following pair of sets equal? Give reasons. (i) A = {2, 3}; B = {x:xis solution ofx2+ 5x+ 6 = 0} (ii) A = {x:xis a letter in the word FOLLOW}; B = {y:yis a letter in the word WOLF} Solution: (i)A = {2, 3}; B = {x:xis a solution ofx2+ 5x+ 6 = 0} The equationx2+ 5x+ 6 = 0 can be solved as:x(x+ 3) + 2(x+ 3) = 0(x+ 2)(x+ 3) = 0x= 2 orx= 3 A = {2, 3}; B = {2, 3}A B (ii)A = {x:xis a letter in the word FOLLOW} = {F, O, L, W} B = {y:yis a letter in the word WOLF} = {W, O, L, F} The ord...

Although both CO2 and H2O are triatomic molecules, the shape of H2O molecule is bent while that of CO2 is linear.

Question: Although both CO2and H2O are triatomic molecules, the shape of H2O molecule is bent while that of CO2is linear. Explain this on the basis of dipole moment. Solution: According to experimental results, the dipole moment of carbon dioxide is zero. This is possible only if the molecule is linear so that the dipole moments of CO bonds are equal and opposite to nullify each other. Resultant= 0 D H2O, on the other hand, has a dipole moment value of 1.84 D (though it is a triatomic molecule a...

What happens to the respiratory process in a man going up a hill?

Question: What happens to the respiratory process in a man going up a hill? Solution: As altitude increases, the oxygen level in the atmosphere decreases. Therefore, as a man goes uphill, he gets less oxygen with each breath. This causes the amount of oxygen in the blood to decline. The respiratory rate increases in response to the decrease in the oxygen content of blood. Simultaneously, the rate of heart beat increases to increase the supply of oxygen to blood....

In the following, state whether A = B or not:

Question: In the following, state whether A = B or not: (i) A = {a,b,c,d}; B = {d,c,b,a} (ii) A = {4, 8, 12, 16}; B = {8, 4, 16, 18} (iii) A = {2, 4, 6, 8, 10}; B = {x:xis positive even integer andx 10} (iv) A = {x:xis a multiple of 10}; B = {10, 15, 20, 25, 30 ...} Solution: (i)A = {a,b,c,d}; B = {d,c,b,a} The order in which the elements of a set are listed is not significant. A = B (ii)A = {4, 8, 12, 16}; B = {8, 4, 16, 18} It can be seen that 12 A but 12 B. A B (iii)A = {2, 4, 6, 8, 10} B = {...

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