Abundance and Isotopes

Q.

The relation between bond order and the total number of resonating forms(R) is given as:

1. BO α R

2. BO = R

3. BO α 1/R

4. BO does not depend upon R

Q. Vapour density of a volatile subs†an ce is 4 in comparison to methane (CH_4=1).Its molecular mass will be: (a) 8 (b) 2 (c) 64 (d) 12

Q. double bond equivalent of cubane i

Q. 104. What is the most probable distance from thenucleus at which a 2p electron will be found in theH-atom? (1) 53 pm (3) 212 pm (2) 106 pm (4) 26.5 pm

Q. equal mass of oxygen, hydrogen and methane are taken in a container in identical conditions. what is the ratio of their moles?

Q. total no. of oxygen atoms present in the mixture containing 8g O_2, 16g O_3 and 6.8 g C_3O_2

Q.

What is common for H+, D+ and T+

1. No of electrons

2. No of protons

3. No of neutrons

4. Activation energy

Q. What is the total no. of electrons present in 1.6g of methane ?

Q.

Is $U-235$ Radioactive?

Q. Choose the correct statement with respect to ortho hydrogen:
Statement-I: In ortho hydrogen, the spin of both nuclei are in same direction.
Statement-II: Ortho hydrogen is more abundant than para hydrogen at room temperature.
Statement-III: Thermal conductivity of ortho hydrogen is more than para hydrogen.

1. I, III
2. I, II
3. II, III
4. I, II, III

Q.

There are more neutrons in Uranium-238 than in Uranium-235.

1. True
2. False

Q. Q2-WHAT IS LINE SPECTRUM OF HYDROGEN?

Q.

Energy required to dissociate 4 g of gaseous hydrogen into free gaseous atoms is 208 kcal at 25^oC. The bond energy of H-H bond will be:

1. 1040 kcal

2. 10.4 kcal

3. 104 kcal

4. 1.04 kcal

Q. Which of the following is same for both normal hydrogen and deuterium?

1. Freezing point

2. Bond energy

3. Bond length

4. Boiling point

Q. 86.Why S-S bond energy is more than O-O inspite of atomic size O is less than S.As we know that bond energy is inversly proportional to atomic size??

Q. Which property is same for both normal hydrogen and deuterium.

1. Boiling point
2. Freezing point
3. Bond energy
4. Bond length

Q. 1 mole of PCl_5 taken at 5atm, dissociates into PCl_3 and Cl_2to the extent of 50% Thus, K_{p }is: (1) 2.5 (2) 1.67 (3) 0.5 (4) 2.0

Q.

GeX₄ is more stable than GeX₂ ehereas PbX₂ is more stable than PbX₄ . why?

Q. $H_1^1,H_1^2,H_1^3$ differs in their

1. Atomic radius
2. Chemical properties
3. Position in the periodic table
4. Physical properties

Q. Why there are so many lines in hydrogen spectrum?

Q. Q 5/30 Addition of an electron to a neutralgaseous atom always leads to(I) Formation of an anion.(II) Liberation of energy.(III) Decrease in proton/electron ratio.

Q. Tritium is the only radioactive isomer of hydrogen.

1. True
2. False

Q. Which of the following has high melting point?

1. $H_2$
2. $D_2$
3. $T_2$
4. Both A and B

Q. Free radicals contain odd no. of electron but why are they still electrically nuetral?

Q. In nuclear transmutation Tritium is obtained from

1. $N_7^{14}$
2. $C_7^{14}$
3. $L{i}_3^6$
4. $O_8^{16}$

Q. Calulate the no of moles in 6.023×10^{23}atoms of O in CO_{

Q. why is energy required for ionization potential

Q. Q 15. The equilibrium constant for the ring-flip of fluorocyclohexane is 1.5 at 25^o C. Calculate the percentage of the axial conformer at the temperature.

Q. Q. Which transition of the hydrogen electron in the visible region causes the maximum release of energy?