6 of each ....................
Explanation:
There are two type of reaction possible , i.e. , exothermic and endothermic reaction ,
Exothermic reaction -
The type of reaction in which energy in the form of heat or light is released , is known as exothermic reaction ,
The reaction mixture usually get heated after the reaction .( temperature increases ) .
The sign of ΔH of an exothermic reaction is negative .
Similarly ,
Endothermic reaction -
The type of reaction in which energy is absorbed in the form of heat is known as endothermic reaction .
The reaction mixture usually get cooled after the reaction .( temperature decreases ) .
The sign of ΔH of an Endothermic reaction is positive .
a. dry ice evaporating ,
<u>Endothermic reaction , ΔH = positive .</u>
b. a sparkler burning ,
<u>Exothermic reaction ΔH = negative . </u>
c. the reaction that occurs in a chemical cold pack often used to ice athletic injuries
<u>Endothermic reaction , ΔH = positive . </u>
Answer: Accountant!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Explanation:
Answer : The acid dissociation constant Ka of the acid is, ![8.7\times 10^{-5}](https://tex.z-dn.net/?f=8.7%5Ctimes%2010%5E%7B-5%7D)
Explanation :
First we have to calculate the concentration of hydrogen ion.
![pH=-\log [H^+]](https://tex.z-dn.net/?f=pH%3D-%5Clog%20%5BH%5E%2B%5D)
Given: pH = 4.06
![4.06=-\log [H^+]](https://tex.z-dn.net/?f=4.06%3D-%5Clog%20%5BH%5E%2B%5D)
![[H^+]=8.71\times 10^{-5}M](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3D8.71%5Ctimes%2010%5E%7B-5%7DM)
The dissociation of acid reaction is:
![HA\rightarrow H^++A^-](https://tex.z-dn.net/?f=HA%5Crightarrow%20H%5E%2B%2BA%5E-)
Initial conc. c 0 0
At eqm. c-cα cα cα
Given:
Degree of dissociation = α = 0.10 % = 0.001
![[H^+]=c\alpha](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3Dc%5Calpha)
![8.71\times 10^{-5}=c\times 0.001](https://tex.z-dn.net/?f=8.71%5Ctimes%2010%5E%7B-5%7D%3Dc%5Ctimes%200.001)
![c=0.0871M](https://tex.z-dn.net/?f=c%3D0.0871M)
The expression of dissociation constant of acid is:
![K_a=\frac{[H^+][A^-]}{[HA]}](https://tex.z-dn.net/?f=K_a%3D%5Cfrac%7B%5BH%5E%2B%5D%5BA%5E-%5D%7D%7B%5BHA%5D%7D)
![K_a=\frac{(c\times \alpha)\times (c\times \alpha)}{(c-c\alpha)}](https://tex.z-dn.net/?f=K_a%3D%5Cfrac%7B%28c%5Ctimes%20%5Calpha%29%5Ctimes%20%28c%5Ctimes%20%5Calpha%29%7D%7B%28c-c%5Calpha%29%7D)
Now put all the given values in this expression, we get:
![K_a=\frac{(0.0871\times 0.001)\times (0.0871\times 0.001)}{(0.0871-0.0871\times 0.001)}](https://tex.z-dn.net/?f=K_a%3D%5Cfrac%7B%280.0871%5Ctimes%200.001%29%5Ctimes%20%280.0871%5Ctimes%200.001%29%7D%7B%280.0871-0.0871%5Ctimes%200.001%29%7D)
![K_a=8.7\times 10^{-5}](https://tex.z-dn.net/?f=K_a%3D8.7%5Ctimes%2010%5E%7B-5%7D)
Thus, the acid dissociation constant Ka of the acid is, ![8.7\times 10^{-5}](https://tex.z-dn.net/?f=8.7%5Ctimes%2010%5E%7B-5%7D)