Answer: The definition of an endothermic reaction is that the products have higher energy than the reactants, resulting in a positive enthalpy of reaction.
Explanation:
Answer:
In this experiment, the period of the pendulum is the dependent variable. There are three independent variables: the pendulum mass, the amplitude of the swing, and the length of the pendulum string.
Explanation:
Answer : The value of
of the weak acid is, 4.72
Explanation :
First we have to calculate the moles of KOH.


Now we have to calculate the value of
of the weak acid.
The equilibrium chemical reaction is:

Initial moles 0.25 0.03 0
At eqm. (0.25-0.03) 0.03 0.03
= 0.22
Using Henderson Hesselbach equation :
![pH=pK_a+\log \frac{[Salt]}{[Acid]}](https://tex.z-dn.net/?f=pH%3DpK_a%2B%5Clog%20%5Cfrac%7B%5BSalt%5D%7D%7B%5BAcid%5D%7D)
![pH=pK_a+\log \frac{[HK]}{[HA]}](https://tex.z-dn.net/?f=pH%3DpK_a%2B%5Clog%20%5Cfrac%7B%5BHK%5D%7D%7B%5BHA%5D%7D)
Now put all the given values in this expression, we get:


Therefore, the value of
of the weak acid is, 4.72
The kind of energy released when atoms are rearranged to form new bonds is called Chemical energy.