Answer:
Zn(s) → Zn⁺²(aq) + 2e⁻
Explanation:
Let us consider the complete redox reaction:
Zn(s) + 2HCl(aq) → ZnCl₂(aq) + H₂(g)
This is a redox reaction because, both oxidation and reduction is simultaneously taking place.
- Oxidation (loss of electrons or increase in the oxidation state of entity)
- Reduction (gain of electrons or decrease in the oxidation state of the entity)
- An element undergoes oxidation or reduction in order to achieve a stable configuration. It can be an octet configuration. An octet configuration is that of outer shell configuration of noble gas.
Here Zn(s) is undergoing oxidation from OS 0 to +2
And H in HCl (aq) is undergoing reduction from OS +1 to 0.
Therefore, for this reaction;
Oxidation Half equation is:
Zn(s) → Zn⁺²(aq) + 2e⁻
Reduction Half equation is:
2H⁺ + 2e⁻ → H₂(g)
Conduction - by touch
Convection - hot air rises, cold air sinks
Insulation - to insulate or capture heat
Radiation - by waves
Direct contact means touch, therefore the answer would be conduction.
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Answer:
Explanation:
Diethyl malonate is more acidic than monocarbonyl compounds (pKa=13) due to their alpha hydrogens being attached to two carbonyl groups. Thus, the <u>malonic ester is easily converted to its enolate ion by reaction with sodium ethoxide in ethanol</u>. The product of the alkylation of the malonic ester leaves a <u>hydrogen atom acid in an alpha position</u>, so the alkylation process can be repeated a second time to produce a dialkylated malonic ester.
In this case, when urea is treated with diethyl malonate in the presence of sodium ethoxide base,<u> the second alkylation step occurs intramolecularly</u> to generate a cyclic product, barbituric acid.
