According to Henderson–Hasselbalch Equation,
pH = pKa + log [Nitrate] / [Nitric Acid]
As, Ka of Nitric Acid = 7.1 × 10⁻⁴
So,
pKa = -log [ 7.1 × 10⁻⁴ ]
pKa = 3.148
So, pH = 3.148 + log [Nitrate] / [Nitric Acid]
3.90 = 3.148 + log [Nitrate] / [Nitric Acid]
3.90 - 3.148 = log [Nitrate] / [Nitric Acid]
0.752 = log [Nitrate] / [Nitric Acid]
Taking Antilog on both sides,
[Nitrate] / [Nitric Acid] = 5.64
We have gravity here on earth while in space there’s none
A. is a hypothesis because hypotheses are usually in the form of if-then statements.
Equation is as follow,
Fe₂O₃ + 3 CO → 2 Fe + 3 CO₂
Oxidation:
3 CO → 3 CO₂
Oxidation state of C in CO is +2, and that in CO₂ is +4. So, carbon has lost 2 electrons per mole and 6 electrons per 3 moles hence,
3 CO → 3 CO₂ + 6 e⁻
Reduction:
Fe₂O₃ → 2 Fe
Oxidation state of Fe in Fe₂O₃ is +3 per atom, and that in Fe is 0. So, Iron has gained 3 electrons per atom and 6 electrons per 2 atoms hence,
Fe₂O₃ + 6e⁻ → 2 Fe
Result:
Iron in Fe₂O₃ has been reduced in this reaction and has played a role of oxidizing agent by oxidizing carbon from +2 state to +4 state.
Answer: Here comes the role of another formula, which we refer to as the structural formula and that is CH3OH for methanol. The structural formula gives us an additional information that carbon is attached to three hydrogen atoms and one oxygen atom.
