Answer:
2H₂O (liq) + 2e⁻⇒ H₂ (g) + 2OH⁻ (aq)
Explanation:
In reduction-oxidation reaction two reactions take place, one is oxidation and the other is reduction reaction. In an oxidation reaction, there is the loss of an electron whereas in the reduction reaction there is gain of electron occus.
Reduction reaction occurs on the cathode, in a reduction of water there is gain of 2 electrons to gaseous hydrogen in basic aqueous solution. half-reaction for the reduction of liquid water to gaseous hydrogen in basic aqueous solution-
2H₂O (liq) + 2e⁻⇒ H₂ (g) + 2OH⁻ (aq)
Answer:
<u>The incorrect choice is the last one:</u>
- <em>In the Leucipo and Democritus atomic model, electrons had negative charges.</em>
Explanation:
The translation of the question is:
Choose the incorrect statement. *
- Matter is everything that has mass and occupies volume.
- Mass and weight are different quantities. Mass is a measure of how much matter an object has, and weight is a measure of the gravitational pull force suffered by the object.
- Dalton's atomic model has similarities to the atomic model described by Leucipo and Democritus.
- Dalton thought that atoms of the same element could not combine, as they developed mutual repulsion.
- In the Leucipo and Democritus atomic model, electrons had negative charges.
<h2>Solution</h2>
The <em>last statement is false</em> because Leucipo and Democritus thought that the atom was an indivisible particle. This is, they did not think there were subatomic particles, such as electrons. Furthermore, the idea of a particle with a negative charge was developed much time (centuries) later.
As for the other statements:
- <em>Matter is everything that has mass and occupies volume</em>: this is the current definition of matter; for instance, wood, air, atoms, have mass and occupy volume. Thougths, feelings do not have either mass or occupy a volume, they are not matter.
- <em>Mass and weight are different quantities</em>. <em>Mass is a measure of how much matter an object has, and weight is a measure of the gravitational pull force suffered by the object</em>. Indeed, the mass is determined by the number of atoms of the substance, but weight is the force of attraction from Earth (or other planet, if the object is in other planet). Mass does not change with the location; weight does.
- <em>Dalton's atomic model has similarities to the atomic model described by Leucipo and Democritus</em>: sure. This is a hystorical question. Leucippus and Democritus were two Greek phylosophers who believed that the matter was formed by tiny solid particles, the atom.
- <em>Dalton thought that atoms of the same element could not combine, as they developed mutual repulsion</em>. In the times of Dalton, when he developed the law of multiple proportions, atoms of a same kind were thought to repel each other.
Answer:
Azide synthesis is the first method on the table of synthesis of primary amines. The Lewis structure of the azide ion, N3−, is as shown below.
an azide ion
An “imide” is a compound in which an N−−H group is attached to two carbonyl groups; that is,
imide linkage
You should note the commonly used trivial names of the following compounds.
phthalic acid, phthalic anhydride, and phthalimide
The phthalimide alkylation mentioned in the reading is also known as the Gabriel synthesis.
If necessary, review the reduction of nitriles (Section 20.7) and the reduction of amides (Section 21.7).
Before you read the section on reductive amination you may wish to remind yourself of the structure of an imine (see Section 19.8).
The Hofmann rearrangement is usually called the Hofmann degradation. In a true rearrangement reaction, no atoms are lost or gained; however, in this particular reaction one atom of carbon and one atom of oxygen are lost from the amide starting material, thus the term “rearrangement” is not really appropriate. There is a rearrangement step in the overall degradation process, however: this is the step in which the alkyl group of the acyl nitrene migrates from carbon to nitrogen to produce an isocyanate.
Explanation:
Answer:
All the elements in one group have the same number of valence electrons. ... Since elements in a group have the same number of valence electrons, they behave similarly in chemistry. An example would be the alkali metals (excepting hydrogen. Hydrogen is in this group only because it has one valence electron.
Explanation:
