Chemical change
Hope this helps!
<span>The relationship between the number of carbon atoms and boiling point is inversely proportional. In the alkane series of hydrocarbons, as the number of carbon atoms decreases, the normal boiling point of the compounds decreases. The reason behind this is that longer chains of molecules require more energy to separate the bonds while shorter chains or molecules with lower number of carbon atoms require less energy to break away from each other. Thus, low carbon molecules have lower boiling point.</span>
Answer:
D. Ni²⁺
Explanation:
We know at once that the answer cannot be A or C, because Ni and Cu are already in their lowest oxidation states.
The correct answer must be either B or D.
An electrolytic cell is the opposite of a galvanic cell. In the former, the reaction proceeds spontaneously. In the latter, you must force the reaction to occur.
One strategy to solve this problem is:
- Look up the standard reduction potentials for the half reaction·
- Figure out the spontaneous direction.
- Write the equation in the reverse direction.
1. Standard reduction potentials
E°/V
Cu²⁺ + 2e⁻ ⟶ Cu; 0.3419
Ni²⁺ + 2e⁻ ⟶ Ni; -0.257
2. Galvanic Cell
We reverse the direction of the more negative half cell and add.
<u>E°/V
</u>
Ni ⟶ Ni²⁺ + 2e⁻; 0.257
<u>Cu²⁺ + 2e⁻ ⟶ Cu; </u> 0.3419
Ni + Cu²⁺ ⟶ Cu + Ni²⁺; 0.599
This is the spontaneous direction.
Cu²⁺ is reduced to Cu.
3. Electrochemical cell
<u>E°/V</u>
Ni²⁺ + 2e⁻ ⟶ Ni; -0.257
<u>Cu ⟶ Cu²⁺ + 2e⁻; </u> <u>-0.3419</u>
Cu + Ni²⁺ ⟶ Ni + Cu²⁺; -0.599
This is the non-spontaneous direction.
Ni²⁺ is reduced to Ni in the electrolytic cell.
Answer:
HX (aq) + H₂O (l) ⇄ H₃O⁺ (aq) + X⁻ (aq)
Acid Base Conj. acid Conj. base
Explanation:
The equation is:
HX (aq) + H₂O (l) ⇄ H₃O⁺ (aq) + X⁻ (aq)
This is the typical equilibrium for a weak acid. It would complete if we notice the Ka.
HX (aq) + H₂O (l) ⇄ H₃O⁺ (aq) + X⁻ (aq) Ka
1 mol of hypothetic HX acid react to 1 mol of water in order to release a proton and make hydronium and generate the X⁻ anion.
HX will be the acid, in this case a weak one and water will be the base. Water is able to accept a proton to make itslef hydronium
Hydronium is the conjugate acid.
The X⁻ will be the conjugate strong base.
This ion can generate the acid form again, that's why it is strong, because it can make hydrolisis.
X⁻ (aq) + H₂O (l) ⇄ HX (aq) + OH⁻(aq) Kb
In this case, the anion will be the conjugate base which it takes a proton from water (acid form) to make a conjugate acid, the HX and a conjugate base, OH⁻
