There are two ways to solve this problem. We can use the ICE method which is tedious and lengthy or use the Henderson–Hasselbalch equation. This equation relates pH and the concentration of the ions in the solution. It is expressed as
pH = pKa + log [A]/[HA]
where pKa = - log [Ka]
[A] is the concentration of the conjugate base
[HA] is the concentration of the acid
Given:
Ka = 1.8x10^-5
NaOH added = 0.015 mol
HC2H3O2 = 0.1 mol
NaC2H3O2 = 0.1 mol
Solution:
pKa = - log ( 1.8x10^-5) = 4.74
[A] = 0.015 mol + 0.100 mol = .115 moles
[HA] = .1 - 0.015 = 0.085 moles
pH = 4.74 + log (.115/0.085)
pH = 4.87
Hydrogen and oxygen are different elements.
when two or more elements combine, they form a compound
hence, two molecules of hydrogen and one molecule of oxygen combine to form water as a compound
Answer:
magnification and resolution
Explanation:
Two parameters are especially important in microscopy: magnification and resolution. Magnification is a measure of how much larger a microscope (or set of lenses within a microscope) causes an object to appear.
Answer : The correct option is, increase amplitude.
Explanation :
Amplitude : It is a measure of the size of sound waves.
The loudness of sound is depend on the amplitude of the sound wave. That means the more the amplitude, the louder will be the sound and the less the amplitude, the low will be the sound.
The loudness of sound does not depend on the tension and wavelength.
Therefore, the correct answer is, increase amplitude.
Answer:- 0.138 M
Solution:- The buffer pH is calculated using Handerson equation:
acts as a weak acid and 
as a base which is pretty conjugate base of the weak acid we have.
The acid hase two protons(hydrogen) where as the base has only one proton. So, we could write the equation as:
Phosphoric acid gives protons in three steps. So, the above equation is the second step as the acid has only two protons and the base has one proton.
So, we will use the second pKa value. The acid concentration is given as 0.10 M and we are asked to calculate the concentration of the base to make a buffer of exactly pH 7.00.
Let's plug in the values in the equation:
Taking antilog:
On cross multiply:
[base] = 1.38(0.10)
[base] = 0.138
So, the concentration of the base that is required to make the buffer is 0.138M.
