The pH of a 10^-10M - NaOH solution is

• 10

• 7.01

• 6.99

• 4

Which has minimum solubility?

• Bi₂S₃

• Ag₂S

• CoS

• PbS

Ratio of molecular weights of A and B is $\frac{4}{25}$ then ratio of rates of diffusion will be

• 5 : 1

• 5 : 2

• 25 : 3

• 25 : 4

H-bond is strongest in

• C₂H₅OH

• H-F

• H₂O

• CH₃COCH₃

a/ V² given in van der Waal's equation is for

• internal pressure

• inter molecular attraction

• both (1) and (2)

• temperature correction

Hybridization of 1 and 2 carbon atom in

$\stackrel{1}{\mathrm{C}}$H₂ = $\stackrel{2}{\mathrm{C}}$ = CH₂ are

• sp, sp

• sp², sp²

• sp², sp

• sp³, sp²

C_(dia) + O₂ $\to$ CO₂; $∆\mathrm{H}$ = - 395.4 kJ/ mol

C_(gr) + O₂ $\to$CO₂; $∆$H   = - 393.5 kJ/ mol

C_(gr) $\to$C_(dia); $∆$H = ?

• -3.8

• -1.9

• +3.8

• +1.9

The internal energy of a substance

• decrease with increase in temperature

• increase with increase in temperature

• remains unaffected with change in temperature

• calculated by E = mc²

In an isothermal process

• $∆\mathrm{H} = ∆\mathrm{E}\hspace{0.17em}+\hspace{0.17em}\mathrm{P}∆\mathrm{V}$

• $∆\mathrm{H} = \mathrm{W}$

• $∆\mathrm{H} = ∆\mathrm{E}$

• $∆\mathrm{H} =\mathrm{S}∆\mathrm{T}$

Number of orbitals in L energy level

• 1

• 2

• 3

• 4