Answer:
20.67 kcal of energy is released.
Explanation:
It is given that, an exothermic reaction releases 86.5 kJ. We need to convet kJ to calories.
Since,
1 kcal = 4.184 kJ
So,
1 kJ = 0.239 kcal
For 86.5 kJ,
86.5 kJ = (0.239 × 86.5) kcal
86.5 kJ = 20.67 kcal
So, 20.67 kcal of energy is released.
Answer:
134.8 seconds is the half-life (in seconds) of the reaction for the initial
concentration
Explanation:
Half life for second order kinetics is given by:

Integrated rate law for second order kinetics is given by:

= half life
k = rate constant
= initial concentration
a = Final concentration of reactant after time t
We have :

Initial concentration of ![C_2F_4=[a_o]=\frac{0.438 mol}{2.42 L}=0.1810 mol/L](https://tex.z-dn.net/?f=C_2F_4%3D%5Ba_o%5D%3D%5Cfrac%7B0.438%20mol%7D%7B2.42%20L%7D%3D0.1810%20mol%2FL)
Rate constant = k = 



134.8 seconds is the half-life (in seconds) of the reaction for the initial
concentration
The answer is D. Ne, which stands for Neon.
(3) Cl2(g) <==> Cl2(l), because it has an equilibrium between the two phases of liquid and gas.