Answer:
True
Explanation:
Theories are ideas which are used to make predictions
Answer: 0.0345 sec
Explanation:
Rate law says that rate of a reaction is directly proportional to the concentration of the reactants each raised to a stoichiometric coefficient determined experimentally called as order.
![Rate=k[H_3PO_4]^2](https://tex.z-dn.net/?f=Rate%3Dk%5BH_3PO_4%5D%5E2)
k= rate constant = 
Expression for rate law for first order kinetics is given by:
where,
k = rate constant
t = age of sample
a = let initial amount of the reactant
a - x = amount left after decay process
for completion of 20 % of reaction
The time taken for the concentration of 
to decrease to 20% to its natural value is 0.0345 sec
Answer:
C.
Explanation:
Phase change is physical.
The kc is a representation of how fast the reaction proceeds to their products when it has achieved equilibrium. The activation energy for the forward and the one for the reverse
reaction are similar because they attained chemical equilibrium. A chemical
equilibrium happens when both of the reactant and products achieve the same
concentration. An example is the process of melting and freezing. Melting and freezing for a given
substance occurs at the same temperature. Because the temperature at which the
solid starts to melt is also the temperature at which the liquid starts to
freeze. They are at chemical equilibrium.
