Archives

How many pi bonds are present in the molecule of CH3 – CH = CH – C = CH?

(A) 2 bonds (B) 3 bonds (C) 8 bonds (D) 9 bonds The Correct Answer is (B) 3 bonds Solution: There are three bonds present... View Article

How many sigma bonds are present in the molecule of dicyanoethene (CN−CH=CH−CN)?

(A) 2 sigma bonds (B) 3 sigma bonds (C) 5 sigma bonds (D) 7 sigma bonds The Correct Answer is (D) 7 sigma bonds Solution: The structure of... View Article

An element with the atomic number 19 will most likely combine chemically with the element whose atomic number is :

(A) 11 (B) 17 (C) 18 (D) 20 The Correct Answer is (B) 17 Solution: An element with the atomic number 19 will most likely combine chemically... View Article

Assertion: PF5, SF6 and H2SO4 are examples of expanded octet molecules.Reason: Octet rule is not applicable to the second-period elements of the periodic table.

(A) Both Assertion and Reason are false. (B) Assertion is true, but Reason is false. (C) Both Assertion and Reason are true. The reason is... View Article

Assertion: HNO3 is a stronger acid than HNO2. Reason: In HNO3 there are two nitrogen to oxygen bonds whereas in HNO2 there is only one.

(A) Both Assertion and Reason are false. (B) Assertion is true, but Reason is false. (C) Both Assertion and Reason are true. The reason is... View Article

Which of the following oxide of iodine is used in the estimation of carbon monoxide?

(A) I2O4 (B) I2O5 (C) I2O6 (D) I2O7 The Correct Answer is (B) I2O5 Solution: Iodine peroxide [ I2O5] is used in the estimation of carbon... View Article

Which of the following oxoanions contains all equivalent M−O bonds?

(A) (B) (C) (D) Both (A) and (B) The Correct Answer is (D) Both (A) and (B) Solution: (A) In the permanganate ion, all the Mn − O... View Article

Calculate the ratio of energies of 2nd orbits of H, He+ and Li+2.

(A) 1 : 4 : 9 (B) 2 : 4 : 9 (C) 3 : 6 : 9 (D) 4 : 8 : 9 The Correct Answer is (A) 1: 4: 9 Solution: The energy of electrons in... View Article

Silver crystallises in the fcc lattice. If the edge length of the cell is 4.07 * 10-8 cm and density is 10.5 g cm-3.Calculate the atomic mass of metal.

Solution: As we know: Density (D) = Given: Density (D) = 10.5 g cm-3 Number of atoms per unit cell (Z) = 4 Atomic mass (M)=? Avogadro's... View Article

The molar specific heat at a constant pressure of an ideal gas is (7/2) R. The ratio of specific heat at constant pressure to that at constant volume is:

(A) 5/7 (B) 7/5 (C) 8/7 (D) 9/7 The Correct Answer is (B) 7/5 Solution: Therefore r = Explore more such questions and answers at BYJU'S.... View Article

An alkyl halide reacts with alcoholic ammonia in a sealed tube, the product formed will be:

(A) Primary amine (B) Secondary amine (C) Tertiary amine (D) All Of These The Correct Answer is (D) All Of These Solution: When an... View Article

If a polynomial 2x^2 – 7x-1 is divided by (x + 3), then the remainder is

Let the given polynomial be f(x) =2x2 - 7x - 1 Using the remainder theorem, we can write f(-3) = 2(-3)2 - 7(-3) - 1 f(-3) = 2(9) +21 - 1... View Article

If P(9a−2,−b) divides the line segment joining A(3a+1,−2) and B(8a,5) in the ratio 3:1. Find the value of a and b.

Given that, P divides the line segment AB in the ratio of 3: 1. A (3a+1 , -2) = (x1, y1) B (8a, 5) = (x2, y2) m + n = 4 By using the... View Article

If the curves ax^2 +4xy+2y^2 +x+y+5=0 and ax^2+6xy+5y^2+2x+3y+8=0 intersect at four con-cyclic points then the value of a is

As we know that, any second degree curve that passes through the intersection of the given curves is ax2 + 4xy + 2y2 + x + y + 5 + λ ( ax2... View Article

Root 83 simplified

As 83 is not a perfect square, we won’t get the square root of 83 as a whole number. Now, 92 < 83 < 102 That is, the square root of 83... View Article

Find the missing number in the figure which follows the same pattern

In the figure, 28 = ( 3 + 4 ) × (5 - 3 + 2) Therefore, for the second figure 12 = (8 + 4) × (8 - 8 + 1) The missing number is 1... View Article

In 1 L saturated solution of AgCl(Ksp AgCl = 1.6 * 10-10), 0.1 mol of CuCl (Ksp CuCl = 1.0 * 10-6) is added. The resultant concentration of Ag+ in the solution is 1.6 * 10-x. Calculate the value of x.

(A) 3 (B) 5 (C) 7 (D) 9 The Correct Answer is (C) 7. Solution: The value of x is 7. The solubility product of CuCl is 1.0 * 10-6... View Article

Which kind of isomerism is exhibited by octahedral [CO(NH3)4 Br2]Cl?

(A) Geometrical isomerism (B) Optical and ionisation isomerism (C) Geometrical and optical isomerism (D) Geometrical and ionisation... View Article

Which of the following gas is formed when an acid reacts with a metal carbonate or metal hydrogen carbonate?

(A) Hydrogen (B) Carbon dioxide (C) Carbon monoxide (D) All of the above. The Correct Answer is (B) Carbon dioxide. Solution: Acid... View Article

Prove that the relative lowering of the vapour pressure of a solution is equal to the mole fraction of non-volatile solute present in the solution.

Solution: According to Raoult’s law, for dilute solutions containing non-volatile solute, the relative lowering of vapour pressure, is equal... View Article

M	T	W	T	F	S	S
					1	2
3	4	5	6	7	8	9
10	11	12	13	14	15	16
17	18	19	20	21	22	23
24	25	26	27	28	29	30
31