The answer is mean,mode and median
Answer : The equilibrium concentration of
in the solution is, 
Explanation :
The dissociation of acid reaction is:

Initial conc. c 0 0
At eqm. c-x x x
Given:
c = 

The expression of dissociation constant of acid is:
![K_a=\frac{[H_3O^+][C_6H_5COO^-]}{[C_6H_5COOH]}](https://tex.z-dn.net/?f=K_a%3D%5Cfrac%7B%5BH_3O%5E%2B%5D%5BC_6H_5COO%5E-%5D%7D%7B%5BC_6H_5COOH%5D%7D)

Now put all the given values in this expression, we get:
![6.3\times 10^{-5}=\frac{(x)\times (x)}{[(7.0\times 10^{-2})-x]}](https://tex.z-dn.net/?f=6.3%5Ctimes%2010%5E%7B-5%7D%3D%5Cfrac%7B%28x%29%5Ctimes%20%28x%29%7D%7B%5B%287.0%5Ctimes%2010%5E%7B-2%7D%29-x%5D%7D)

Thus, the equilibrium concentration of
in the solution is, 
Answer:
0.04 M
Explanation:
Given data:
Mass of Na₂SO₄= 14.2 g
Volume of solution = 2.50 L
Molarity of solution = ?
Solution:
Number of moles of Na₂SO₄:
Number of moles = mass/ molar mass
Number of moles = 14.2 g/ 142.04 g/mol
Number of moles = 0.1 mol
Molarity :
Molarity = number of moles of solute / volume of solution in L
Molarity = 0.1 mol / 2.50 L
Molarity = 0.04 M
Answer:
N₂ = 6.022 × 10²³ molecules
H₂ = 18.066 × 10²³ molecules
NH₃ = 12.044 × 10²³ molecules
Explanation:
Chemical equation;
N₂ + 3H₂ → 2NH₃
It can be seen that there are one mole of nitrogen three mole of hydrogen and two moles of ammonia are present in this equation. The number of molecules of reactant and product would be calculated by using Avogadro number.
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
For example,
Number of molecules of nitrogen gas:
1 mol = 6.022 × 10²³ molecules
Number of molecules of hydrogen:
3 mol × 6.022 × 10²³ molecules/ 1 mol
18.066 × 10²³ molecules
Number of molecules of ammonia:
2 mol × 6.022 × 10²³ molecules/ 1 mol
12.044 × 10²³ molecules