Bohr's atomic model may have not been the accurate atomic model we have in the present, but he helped paved the way for accurate discoveries. His model is also called the planetary model. The nucleus, containing the neutrons and protons are situated at the center of the atom. The electrons are orbiting around the nucleus. The model is illustrated as shown in the attached picture.
PH is calculated using <span>Handerson- Hasselbalch equation,
pH = pKa + log [conjugate base] / [acid]
Conjugate Base = Acetate (CH</span>₃COO⁻)
Acid = Acetic acid (CH₃COOH)
So,
pH = pKa + log [acetate] / [acetic acid]
We are having conc. of acid and acetate but missing with pKa,
pKa is calculated as,
pKa = -log Ka
Putting value of Ka,
pKa = -log 1.76 × 10⁻⁵
pKa = 4.75
Now,
Putting all values in eq. 1,
pH = 4.75 + log [0.172] / [0.818]
pH = 4.072
The type of reaction that is Mg +S→ MgS is a synthesis reaction
<u><em>Explanation</em></u>
Synthesis reaction as refers to as direct combination is a reaction in which two or more chemical species combine to form more complex product.
The reaction of Mg +S → MgS is a synthesis reaction because;
Mg combine with S to form a more complex product MgS
The molarity of solution made by diluting 26.5ml of 6.0ml hno3 to a volume of 250ml is calculated using the following formula
M1V1 = M2V2, where
M1 = molality 1 (6.00m)
V1= volume 1 (26.5 ml)
M2 = molarity 2(?)
v2=volume 2 (250)
M2 = M1V1/V2
M2= 6 x26.5/250 = 0.636 M