31.

Which of the following unit cell having maximum number of atoms ?

• BCC

• HCP

• FCC

• Cubic

Sulphur colloid prepared by

• mechanical dispersion

• oxidation

• electrical dispersion

• reduction

When F₂ reacts with hot and concentrated alkali, then following will be obtained

(i) OF₂

(ii) O₂

(iii) H₂O

(iv) NaF

• (i), (iii) and (iv)

• (ii) and (iii)

• (ii), (iii) and (iv)

• All of the above

Formula for agate is

• Na₂SiO₃

• K₂O.SiO₂.Al₂O₃

• SiO₂

• CaF₂

Colour of colloids depends on which of the following factors ?

• Size

• Mass

• Charge

• Nature

The oxidation potential values of A, B, C and D are -0.03 V, +0.108 V, -0.07 V and +0.1 V respectively. The non-spontaneous cell reaction takes place between

• A and B

• Band D

• D and A

• B and C

Na is used in reduction of Zn salt because

• E°_{Zn (oxi)} > E°_{Na (oxi)}

• E°_{Zn (red)} > E°_{Na (red)}

• E°_{Zn (oxi)} < E°_{Na (oxi)}

• both (a) and (b)

Reduction potentials of A, B, C and D are 0.8 V, 0.79 V, 0.34 V and -2.37 V respectively. Which element displaces all the other three elements?

• B

• A

• D

• C

Complete the following chemical reaction

RCOOH $\underset{∆}{\overset{{\mathrm{P}}_2{\mathrm{O}}_5}{\to }}$

• acid anhydride

• ketone

• aldehyde

• ester

Acetaldoxime on reduction with Na/C₂H₅OH gives

• 2-propanol

• ethyl amine

• acetaldehyde

• ethanol