Froth floatation process is used for the concentration of which one?
Horn silver
Haematite
Bauxite
Cinnabar
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
The half-life period (t1/2) 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
D.
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
Bakelite is the condensation polymer of
C6H5OH and caprolactum
HCHO and phthalic acid
C6H5OH and HCHO
HCHO and ethylene glycol