# +2 Chemistry - 15 One Mark Questions

Ready for the next one mark question practice challenge..Here we go..CBSE board specific questions, +2 Chemistry Syllabus..Give it a go and post your answers to the questions below.

1) If the energy of an electron in the second Bohr orbit of H-atom is –E, what is the energy of the electron in the Bohr's first orbit?

a) 2E

b) –4E

c) –2E

d) 4E

2) The electronegativity of chlorine is calculated by Pauling's scale as:

a) 2.1

b) 4

c) 3.87

d) 2.5

3) What will be the uncertainty in velocity $(\Delta v)$ of a cricket ball (m = 0.15 kg) if the uncertainty position $(\Delta x)$ is of the order of $1\; \dot{A} \;(10^{-10}m)$ ?

a) $3.515 \; \times 10^{-34} \; ms^{-1}$

b) $3.513 \; \times 10^{-24} \; ms^{-1}$

c) $3.513 \; \times 10^{-31} \; ms^{-1}$

d) $3.513 \; \times 10^{-36} \; ms^{-1}$

4) According to Planck's quantum theoy,

a) $E=mc^{2}$

b) $K.E.= \frac{mv^2}{2}$

c) $E = hv$

d) $\lambda = \frac{h}{mc}$

5) The velocity of a particle is $1 \times10^{3} \; ms^{-1}$ and its de Broglie wavelength is $2 \times10^{-6} \; m$, then the mass of the particle is:

a) $3.313 \times10^{-31} \; kg$

b) $2.212 \times10^{-31} \; kg$

c) $6.626 \times10^{-34} \; kg$

d) $6.626 \times10^{-2} \; kg$

6) Which of the following has the lowest ionization potential?

a) K

b) Na

c) Be

d) Mg

7) Which one of the following has the zero electron affinity?

a) Na

b) Cl

c) Ne

d) Si

8) The internuclear distance between $K^{+}$ and $Cl^{-}$ ions in potassium chloride crystal are found to be:

a) $1.54 \;\dot{A}$

b) $2.31 \;\dot{A}$

c) $3.14 \;\dot{A}$

d) $1.93 \;\dot{A}$

9) Find the uncertainty in velocity of an electron if he uncertainty in position is $10^{-4} \;m$. Use uncertainty principle:

a) $0.579 \;ms^{-1}$

b) $5.79 \;ms^{-1}$

c) $0.0579 \;ms^{-1}$

d) $57.9 \;ms^{-1}$

10) Who proposed the uncertainty principle?

a) John Daltton

b) Max Planck

c) Werner Heisenberg

d) Neils Bohr

11) Which one of the following is paramagnetic in nature?

a) $O_^{2}$

b) $H_^{2}$

c) $N_^{2}$

d) $He_^{2}$

12) The velocity of a particle of mass $6.626 \times 10^{-31} \; kg$ with de Broglie wavelength of $5 \times 10^{-11} \; m$ is:

a) $2 \times 10^{-7} \; ms^{-1}$

b) $2 \times 10^{5} \; ms^{-1}$

c) $2 \times 10^{-5} \; ms^{-1}$

d) $2 \times 10^{7} \; ms^{-1}$

13) What will be de Brroglie wavelength of an electron with velocity $10^{7} \; ms^{-1}$

a) $7.28 \times 10^{-10} \; m$

b) $7.28 \times 10^{-9} \; m$

c) $1.28 \times 10^{-11} \; m$

d) $7.28 \times 10^{-11} \; m$

14) How many nodes are possible for 2 s orbital?

a) 1

b) 2

c) 3

d) zero

15) The number of nodes in s orbital of any energy level is equal to:

a) n

b) $2n^{2}$

c) n-1

d) n-2