First, we determine the energy released by the reaction using the heat capacity and change in temperature as such:
Q = cΔT
Q = 32.16 * 0.42
Q = 13.51 kJ
Next, we determine the moles of ammonia formed as the heat of formation is expressed in "per mole".
Moles = mass / molecular weight
Moles = 5/17
Moles = 0.294
Heat of formation = 13.51 / 0.294
The heat of formation of ammonia is 45.95 kJ/mol
As mentioned above, phosphoric acid has 3 pKa values, and after 3 ionization it gives 3 types of ions at different pKa values:
H₃PO₄(aq)
+ H₂O(l) ⇌ H₃O⁺(aq) + H₂PO₄⁻ (aq) pKₐ₁
<span>
</span>H₂PO₄⁻(aq) + H₂O(l) ⇌ H₃O⁺(aq) + HPO₄²⁻ (aq) pKₐ₂
HPO₄²⁻(aq) + H₂O(l) ⇌ H₃O⁺(aq) + PO₄³⁻ (aq) pKₐ₃
At the highest pKa value (12.4) of phosphoric acid, the last OH group will lose its hydrogen. On the picture I attached, it is shown required protonated form of phosphoric acid before reaction whose pKa value is 12.4.
Explanation:
The starch requires a temperature higher than the room temperature (arround 60 °C) to decompose to form simple sugars. This is because the energy required to break the chemical bonds. Also, it may need the action of some specific enzymes (alpha and beta amilase) to break those bonds.
Its true, By definition, an atom is electrically neutral<span> it has the same number of protons as it does electrons, plus some number of neutrons depending on the isotope</span>