Answer:
Examples of Chemical Changes
Burning wood.
Souring milk.
Mixing acid and base.
Digesting food.
Cooking an egg.
Heating sugar to form caramel.
Baking a cake.
Rusting of iron.
A) Cu
Cu + 2HCl --> CuCl2 + H2(g)
Products predicted: Copper(II) choloride and hydrogen gas
B) Mg
Mg + 2HCl --> MgCl2 + H2
Products predicted: magnesium chloride + hygrogen gas
C) Fe
Fe +2 HCl -> FeCl2 + H2, or
2Fe +6 HCl -> 2FeCl3 + 3H2
Products predicted: Iron(II) chloride, iron (III) chloride and hydrogen gas.
Explanation:
The chemical reaction given in the question is as follows -
MnO₄⁻ (aq) + 8H⁺ (aq) + 5e⁻ → Mn²⁺ (aq) + 4H₂O (l)
NO₃⁻ (aq) + 4H⁺ (aq) + 3e⁻ → NO (g) + 2H₂O (l)
As we know , the value for reduction potential are -
Mn²⁺ = + 1.51 V
NO₃⁻ = +0.96 V
From , the data given above , the value of the reduction potential of NO₃⁻ is less than the reduction potential of Mn²⁺ .
Hence ,
NO₃⁻ can not oxidize Mn²⁺ .
Answer:
- <u>Alkaline or basic solution </u>(alkaline and basic means the same)
Explanation:
According to the <em>pH</em>, solutions may be classified as neutral, acidic, or alkaline (basic).
This table shows such classification:
pH classification
7 neutral
> 7 alkaline or basic
< 7 acidic
Thus, since the pH of the solution is 8.3, which is greater than 7, the solution is classified as basic (alkaline).
Additionally, you must learn that pH is a logarithmic scale for the concentration of hydronium ions in the solution.
You can calculate the concentration of hydronium ions using antilogarithm properties:
![pH=-log[H_3O^+]\\ \\ {[H_3O^+]}=10^{-pH}\\ \\ {[H_3O^+]}=10^{-8.3}=0.00000000501](https://tex.z-dn.net/?f=pH%3D-log%5BH_3O%5E%2B%5D%5C%5C%20%5C%5C%20%7B%5BH_3O%5E%2B%5D%7D%3D10%5E%7B-pH%7D%5C%5C%20%5C%5C%20%7B%5BH_3O%5E%2B%5D%7D%3D10%5E%7B-8.3%7D%3D0.00000000501)
NaOH solutions are alkaline solutions, bases, according to Arrhenius model, because they contain OH⁻ ions and release them when ionize in water.
Answer is: the % ionization of hypochlorous acid is 0.14.
Balanced chemical
reaction (dissociation) of an aqueous solution of hypochlorous acid:
HClO(aq) ⇄ H⁺(aq) + ClO⁻(aq).
Ka = [H⁺] · [ClO⁻] / [HClO].
[H⁺] is equilibrium concentration of hydrogen cations or protons.
[ClO⁻] is equilibrium concentration of hypochlorite anions.
[HClO]
is equilibrium concentration of hypochlorous acid.
Ka is the acid
dissociation constant.
Ka(HClO) = 3.0·10⁻⁸.
c(HClO) = 0.015 M.
Ka(HClO) = α² · c(HClO).
α = √(3.0·10⁻⁸ ÷ 0.015).
α = 0.0014 · 100% = 0.14%.