Answer: a) 
: anode
b. 
: cathode
c. 
: anode
Explanation:
Electrochemical cell is a device which converts chemical energy into electrical energy. It consist of two electrodes, anode and cathode.
Oxidation i.e. loss of electrons , which results in an increase in oxidation number occurs over anode.
Reduction i.e. gain of electrons, which results in decrease in oxidation number occurs over cathode.
a. : oxidation : anode
b. : reduction : cathode
c. : oxidation : anode
more reactive metals:
potassium (highest reactivity)
sodium
calcium
magnesium
moderate reactive metals:
aluminium
zinc
iron
lead
least reactive metals:
copper
mercury
silver
gold (least reactivity)
Answer:
Chemical reactivity increases down a group and decreases from left to right of a period.
Explanation:
The higher the ionization energy is, the lower the reactivity is. Since the ionization energy is highest in the top right corner of the periodic table, we can assume that the most reactive elements are in the opposite bottom left corner. This is because the electrons that react are farther away from the nucleus thus experience less attraction to the nucleus (called nuclear shielding). Therefore their electrons are more easily removed than elements that don't ecperience nuclear shielding.
Answer : The ratio of 
to 
is, 
Solution : Given,
= 0.21 atm
The given equilibrium reaction is,
The expression of 
will be,
Now put all the given values in this expression, we get:
Therefore, the ratio of to is,
