Answer: The value of equilibrium constant for reaction is,
Explanation:
The given chemical equations are:
(1)
;
(2)
; 
Now we have to calculate the equilibrium constant for chemical equation as:
; 
We are reversing reaction 2 and multiplying reaction 2 by 2 and then adding both reaction, we get the final reaction.
The equilibrium constant for the reverse reaction will be the reciprocal of that reaction.
If the equation is multiplied by a factor of '2', the equilibrium constant of that reaction will be the square of the equilibrium constant.
If we are adding equations then the equilibrium constants will be multiplied.
The value of equilibrium constant for reaction is:

Now put all the given values in this expression, we get:


Hence, the value of equilibrium constant for reaction is,
Answer : The balanced chemical equation will be:
(i) 
(ii) 
Explanation :
Balanced chemical equation : It is defined as the equation in which total number of individual atoms on the reactant side is equal to the total number of individual atoms on product side.
Part (i):
The balanced chemical equation will be:

This reaction is a single displacement reaction in which most reactive element (potassium) displaces the least reactive element (hydrogen) form their solution.
Part (ii):
The balanced chemical equation will be:

This reaction is a single displacement reaction in which most reactive element (zinc) displaces the least reactive element (magnesium) form their solution.
Answer:
specific heat.
Explanation:
Definition:
The amount of heat required to raise the temperature of one gram of substance by one degree is called specific heat.
Formula:
Q = m. c. ΔT
Q = amount of heat required
m = mass of substance
c = specific heat of substance
ΔT = change in temperature
The substance with greater value of specific heat require more heat to raise the temperature while the substance with lower value will raise its temperature very quickly by absorbing smaller heat.
For example the beach sand gets hot very quickly because of lower specific heat of sand while water is colder than sand because of higher specific heat capacity.
When waves act together, you talk about "interference".
When they reinforce each other, it is "constructive interference".
When they cancel each other, it is "destructive interference".