The property of crystalline solid is not

• anisotropic

• isotropic

• hardness

• denseness

Froth floatation process is used for the concentration of which one?

• Horn silver

• Haematite

• Bauxite

• Cinnabar

A common metal used for the extraction of metals from their oxides by reduction is

• Al

• Fe

• Cr

• Co

Due to Frenkel defect, the density of the ionic solids

• does not change

• decreases

• increases

• may increase or decrease

A first order reaction completed its 20% in 200 minute. How much time it will take to complete its 80%?

• 400 min

• 800 min

• 1400 min

• 1000 min

Which of the following metal is leached by cyanide process?

• Na

• Cu

• Ag

• Fe

The half-life period (t_1/2) for ²⁴¹Am in years, (given that it emits 1.2 × 10¹¹ α-particles per gram per second) is

• 375 yr

• 112 yr

• 615 yr

• 458 yr

If the initial concentration of the reactant is doubled, the time for half reaction is also doubled. The order of the reaction is

• zero

• one

• two

• three

Nylon-6 is made from

• 1, 3-butadiene

• chloroprene

• adipic acid

• caprolactum

40.

Bakelite is the condensation polymer of

• C₆H₅OH and caprolactum

• HCHO and phthalic acid

• C₆H₅OH and HCHO

• HCHO and ethylene glycol