Answer:
0.4
Explanation:
Given parameters:
Mass of NaCl = 0.564g
Mass of KCl = 1.52g
Mass of LiCl = 0.857g
Unknown:
Mole fraction of KCl = ?
Solution:
First, find the number of moles of the given species;
Number of moles =
Molar mass of KCl = 39 + 35.5 = 74.5g/mol
Molar mass of NaCl = 23 + 35.5 = 58.5g/mol
Molar mass of LiCl = 7 + 35.5 = 42.5g/mol
Number of moles of KCl =
= 0.02mol
Number of moles of NaCl =
= 0.0096mol
Number of moles of LiCl =
= 0.02mol
Sum of moles = 0.02mol + 0.0096mol + 0.02mol = 0.0496mol
Mole fraction of KCl =
= 0.4
Answer: a) pH of a 0.1 M vinegar solution is 2.9
b) It is an acid as pH is less than 7
Explanation:
pH or pOH is the measure of acidity or alkalinity of a solution.
pH is calculated by taking negative logarithm of hydrogen ion concentration.
Acids have pH ranging from 1 to 6.9, bases have pH ranging from 7.1 to 14 and neutral solutions have pH equal to 7.
As vinegar is a weak acid, its dissociation is represented as;
![CH_3COOH\rightleftharpoons H^+CH-3COO^-](https://tex.z-dn.net/?f=CH_3COOH%5Crightleftharpoons%20H%5E%2BCH-3COO%5E-)
cM 0 0
So dissociation constant will be:
![K_a=\frac{(c\alpha)^{2}}{c-c\alpha}](https://tex.z-dn.net/?f=K_a%3D%5Cfrac%7B%28c%5Calpha%29%5E%7B2%7D%7D%7Bc-c%5Calpha%7D)
Give c= 0.1 M
![[H^+]=c\times \alpha](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3Dc%5Ctimes%20%5Calpha)
![[H^+]=0.1\times \alpha](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3D0.1%5Ctimes%20%5Calpha)
![1.3\times 10^{-3}=0.1\times \alpha](https://tex.z-dn.net/?f=1.3%5Ctimes%2010%5E%7B-3%7D%3D0.1%5Ctimes%20%5Calpha)
![\alpha=0.013](https://tex.z-dn.net/?f=%5Calpha%3D0.013)
Also ![pH=-log[H^+]](https://tex.z-dn.net/?f=pH%3D-log%5BH%5E%2B%5D)
![pH=-log[1.3\times 10^{-3}]=2.9](https://tex.z-dn.net/?f=pH%3D-log%5B1.3%5Ctimes%2010%5E%7B-3%7D%5D%3D2.9)
Thus pH of a 0.1 M vinegar solution is 2.9
As pH is less than 7, it is an acid.
I need help with this too:(( did u get it?
A characteristic of strong base is that
<span>It removes H+ ions from solution.
</span>
A strong base can dissociate into ions that can react with an acid resulting to the removal of H+ ions from a solution. A weak base only dissociates partially which removes less H+ ions in a solution.