To solve number 18 you have to add the positive and negative to equal zero. For example for 18a it would be K2S ( the 2 is a subscript ) because you need 2 positives to cancel out the 2 negatives.
Henderson-Hasselbalch equation relates the pH with the dissociation constant of the acid. The pH of the buffer solution will be 3.90.
<h3>What is the Henderson-Hasselbalch equation?</h3>
The Henderson-Hasselbalch equation is used to calculate the pH or the concentration of the conjugate base and acid.
The Henderson-Hasselbalch equation can be given as,
pH = pKa + log [A⁻] ÷ [HA]
The dissociation reaction is given as,
HA⁺ + H2O ⇌ H3O⁺ + A⁻
NaA → Na⁺ + A⁻
For this first pKa is calculated as:
pKa = - log (1. 0 x 10⁻⁴)
Substituting the value of pKa in Henderson-Hasselbalch equation pH is determined as:
pH = - log (1. 0 x 10⁻⁴) + log [0.08] ÷ [0.1]
= 4 + (-0.0969)
= 3.90
Therefore, 3.90 is the pH of the solution.
Learn more about Henderson-Hasselbalch here:
brainly.com/question/13151501
#SPJ4
Answer:
The salt will be located in period 6 of the periodic table.
Explanation:
384.72 J is the heat of fusion of the substance.
<h3>What is the heat of fusion? </h3>
It is the change in the value of the enthalpy by providing energy i.e. heat, for a specific quantity of the substance.
Given data:
Heat of fusion =?
Mass of substance = 8.4 g
Unknown:
Amount of energy required to melt the given mass = 45.8 cal
Solution:
To solve this problem, the amount of energy required to melt the substance is given as;
H = m L
m is the mass
L is the heat of fusion
Insert the given parameters and solve;
H = 8.4 g x 45.8 cal = 384.72 J
Hence, 384.72 J is the heat of fusion of the substance.
Learn more about heat of fusion here:
brainly.com/question/19531870
#SPJ2