Answer to Question #66951 in Physical Chemistry for murahi

Question

Question 15 : In a reaction:
2
A
→
B
+
2
C
2A→B+2C
, which of the statement is true?
Rate of formation of B = Rate of disappearance of A
Rate of disappearance of A = Rate of formation of C
Rate of disappearance of A = Rate of formation of B
Rate of formation of C= Rate of formation of B

Question 16 : A beaker with a mixture of ice and water is maintained at equilibrium:
H
2
O
(
s
)
+
h
e
a
t
→
H
2
O
(
l
)
H2O(s)+heat→H2O(l)
; If the temperature of the system is decreased:
No change occurs
The container cacks
Ice melts to form liquid water (shift to the right)
Water freezes to form ice (shifts to the left)

Question 17 : The term — dx/dt in the rate expression refers to the
Average rate of the reaction
increase in concentration of the reactants
instantaneous rate of the reaction
Change in concentration of the reactants with time

Answer 1

Question 15: A – 2 mol, C – 2 mol. So the correct answer: rate of disappearance of A = rate of formation of C.

Question 16: According to the Le Chatelier principle, if a system in equilibrium is influenced from outside by changing any of the conditions (temperature, pressure, concentration), then the equilibrium is shifted in such a way as to compensate for the change, that is, the equilibrium of the reaction shifts in the sides to the opposite active factor. Since the reaction is endothermic, a decrease in temperature leads to a shift in the equilibrium toward the original products, that is, to the left. So the correct answer: Water freezes to form ice (shifts to the left).

Question 17: dx/dt – change in concentration of the reactants with time . So the correct answer: change in concentration of the reactants with time.

Answer: Question 15: rate of disappearance of A = rate of formation of C;
Question 16: water freezes to form ice (shifts to the left);
Question 17: change in concentration of the reactants with time.