For a chemical reaction, mA → xB, the rate law is r = k[A]². If the concentration of A is doubled, the reaction rate will be

• doubled

• quadrupled

• increases by 8 times

• unchanged

Schottky defect in a crystal is observed, when

• unequal number of cations and anions are missing from the lattice

• equal number of cations and anions are missing from the lattice

• an ion leaves its normal site and occupies an interstitial site

• no ion is missing from its lattice site

For 3A → 2B, rate of reaction, +$\frac{\mathrm{d}\left[\mathrm{B}\right]}{\mathrm{dt}}$ is equal to

• $-\frac{3}{2}\frac{\mathrm{d}\left[\mathrm{A}\right]}{\mathrm{dt}}$

• $-\frac{2}{3}\frac{\mathrm{d}\left[\mathrm{A}\right]}{\mathrm{dt}}$

• $+2\frac{\mathrm{d}\left[\mathrm{A}\right]}{\mathrm{dt}}$

• $-\frac{1}{3}\frac{\mathrm{d}\left[\mathrm{A}\right]}{\mathrm{dt}}$

The activation energy of a chemical reaction can be determined by,

• evaluating rate constants at two different temperatures

• changing the concentration of reactants

• evaluating the concentration of reactants at two different temperatures

• evaluating rate constant at standard temperature

35.

Which of the following statements is incorrect with respect to physisorption?

• The forces involved are van der Waals' forces

• More easily liquefiable gases are adsorbed easily

• Under high pressure it results into multimolecular layer on adsorbent surface

• $∆$H_adsorption is low and positive

Sulphur sol contains

• discrete S-atoms

• discrete S molecules

• large aggregates of S molecules

• water dispersed in solid sulphur

Reactions in zeolite catalyst depend on

• pores

• apertures

• size ofcavity

• All of the above

van-Arkel method of refining zirconium involves

• removing all oxygen and nitrogen impurities

• removing CO impurity

• removing hydrogen impurity

• removing silica impurity

The composition of "copper matte" is

• Cu₂S + FeS

• Cu₂S + Cu₂O

• Cu₂S + FeO

• Cu₂O + FeS

The complex formed when Al₂O₃ is leached from bauxite using conc. NaOH solution is,

• Na[Al(OH)₄]

• NaAl₂O₄

• Na[Al(OH)₃]

• Na₂AlO₂