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
Answer: Option (c) is the correct answer.
Explanation:
A chemical reaction is defined as the reaction where a chemical bond will break in order to form a new bond due to the formation of a new substance.
For example, 
Here, NaCl is the new substance that is formed. A chemical reaction will always bring change in chemical composition of a substance.
The production of hydrogen gas from water, the tarnishing of a copper penny, charging a cellular phone and burning a plastic water bottle are all chemical reactions.
Whereas a reaction where no change in chemical composition of a substance takes place is known as a physical reaction.
For example, chopping a log into sawdust will change the shape but it will not bring any change in chemical composition of the substance.
Thus, we can conclude that in the following list, only chopping a log into sawdust is not an example of a chemical reaction.
Balance the chemical equation for the chemical reaction.
Convert the given information into moles.
Use stoichiometry for each individual reactant to find the mass of product produced.
The reactant that produces a lesser amount of product is the limiting reagent.
The reactant that produces a larger amount of product is the excess reagent.
To find the amount of remaining excess reactant, subtract the mass of excess reagent consumed from the total mass of excess reagent given.
Answer:
The rate of forward reaction increases.
Explanation:
- Le Châtelier's principle states that <em>when there is an dynamic equilibrium, and this equilibrium is disturbed by an external factor, the equilibrium will be shifted in the direction that can cancel the effect of the external factor to reattain the equilibrium.</em>
Increasing the volume of oxygen:
will increase the concentration of oxygen (reactants), so the equilibrium will be shifted to the right side (products side) to suppress the effect of increasing the volume of oxygen.
<em>So, the right choice is: The rate of forward reaction increases.
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Density is given by mass divided by the volume of a substance.
In this case the mass is 0.794 g and the volume is 0.82 cm ×1.45 cm ×1.25 cm = 1.48625 cm³.
Therefore, density = 0.794/ 1.48625
= 0.5342 g/cm³
Thus, the density of lithium metal is 0.5342 g/cm³
