Both Co3+ and Pt4+ have a coordination number of six. Which of the following pairs of complexes will show approximately the same electrical conductance for their 0.001M aqueous solutions?
CoCl3 · 4NH3 and PtCl4 . 4NH3
CoCl3 · 3NH3 and PtCl4 · 5NH3
CoCl3 · 6NH3 and PtCl4 · 5NH3
CoCl3 . 6NH3 and PtCl4 . 3NH3
The cubic unit cell of Al (molar mass 27 g mol-1) has an edge length of 405 pm. Its denstiy is 2.7g cm-3. The cubic unit cell is
face centred
body centred
primitive
edge centred
The radioactive isotope of caesium -137 of weight 8 g was collected on 1st February, 2006 and kept in a sealed tube. On 1st July 2006 it was found that only 0.25 g of it remained. The half-life period of the isotope is
37.5 day
30 day
25 day
50 day
The age of a specimen t is realted to the daughter/ parent ratio of number of atoms (D/ P) by the equation (λ = decay constant)
t =
t =
t =
t =
Which one of the following set of units represents the smallest and largest amount of energy respectively?
J and erg
erg and cal
cal and eV
eV and lit-atom
The effciency of enzyme catalysis is due to its capacity to
form a strong enzyme-substrate complex
chage the shape of the substrate
lower the activation energy of the reaction
form a colloidal solution in water
Under which one of the following conditions, does the reaction
CH ≡ CH + CH3OH CH3O-CH=CH2 take place?
NH4OH/ 80°C
conc. H2SO4 / 160°C
CH3OK/ 160- 200°C
Dilute HCl/ THF, 80°C
C.
CH3OK/ 160- 200°C
The above reaction will take place in the presence of CH3OK/ 160-200°C. It can be written as-
CH ≡ CH + CH3OH
Identify the product/s in the following reaction
3CH3CH = CH2 X Product/s + H3BO3
CH3CH2CH2OH
CH3CHOCH3
CH3CH2CHO
CH3CH2OH + CH3OH
Which of the following is not true of carbanions?
The carbon carrying the charge has eight valence electrons
They are formed by heterolytic fission
They are paramagnetic
The carbon carrying the charge is sp3 hybridised