Calculate the mole fraction of solute in the 12 molal aqueous solution of CaCO3.

40 gm metal oxide (MO) contain 4 gm of Oxygen.Calculate the equivalent wt of a metal.

40 gm metal oxide contains 4 gm of Oxygen mean it has 36 gm of metal.

Then Equivalent wt of metal is 

  E_m = (Wt of metal/Wt of Oxygen)×8

  E_m = (36gm /4gm)×8

  E_m = 72 gm equivalent

A metal oxide contains 60% metal by mass. The equivalent weight of metal is ..?

Metal Oxide contains 60% metal by mass means 100g of this oxide has 60 g metal and 40g oxygen.

Equivalent Wt of Metal = (Wt of metal/Wt of Oxygen)×8

E_m = 60×8/40 = 12gm equivalent

Alkenes undergo electrophilic addition reaction and benzene undergoes electrophilic substitution whereas both proceeds through carbocation intermediate. Explain.

Electrons are available in case of alkanes whereas they are delocalized in case 

of benzene. After attack of electrophile a stable delocalized carboncation is 

formed on benzene ring. Whereas a carbocation which can rearrange is formed 

by addition of electrophile on alkane.

How many 1°, 2° , 3° and 4° carbon atoms are present in the following compounds? (CH3)3C – CH(CH3).CH(CH3)2