Which pair of elements below have +3 ionic change?<br> A. Al and Ga<br> B. Sc and Y

If a sample of gold is a cube what is the length of each edge in centimeters

Irina-Kira [14]

<span>This question cannot be answered in actual centimeters unless at least one edge has a known length however it can be written as (length^3) or (length cubed). As an example if the sample of gold cube had one length of 3cm then all lengths would be 3cm on the cube.</span>

4 0

3 years ago

It is true/falseit that when hydrogen cyanide, h c n , dissolves in water, the solution is weakly conducting and acidic in natur

cluponka [151]

False is the correct answer.

8 0

3 years ago

) Predict the product for the following reaction sequence. A) 2,2-dimethylpropanoic acid B) 3,3-dimethyl-2-butanone C) 2,2-dimet

cestrela7 [59]

Answer:

Option C. 2,2-dimethyl-1-propanol

Explanation:

The first attached picture, is the initial reactant.

Now, what happens in each step?, at first we have an alkyl bromide reacting with Mg/ether. This converts the reactant in a grignard reagent, which is often used in several ketones/ladehydes reactions, and even some acid and esthers.

Now, in the second step, we see this grignard reagent, reacting with CO₂ and H₃O⁺. At first, the grignard reagent will attach to the oxygen of the CO₂ by the MgBr, and the carbonated chain will attach to the carbonile. Then in acid medium, the OMGBr leaves the molecule, and form a carboxylic acid.

Finally, in the last step with LiAlH₄ and water, this compound just reduces the carboxylic acid to a primary alcohol, therefore, the only choice available is option c, 2,2-dimethyl-1-propanol.

See picture 2 below for the drawing.

Hope this helps

8 0

3 years ago

Give the structure that corresponds to the following molecular formula and 1H NMR spectrum: C4H10O2: δ 1.36 (3H, d, J = 5.5 Hz);

kondor19780726 [428]

Answer:

For the determination of a structure through its NMR it is necessary to know its molecular formula as well as the delta values, its coupling and the shift of each signal.

The separation produced is called coupling constant J and is measured in Hz. If the split is produced by two equal protons (equal J) a triple signal known as triplet is produced and if produced by three equal protons, the signal is quadruple and is known as quadruplet. The magnitude of the coupling is varied, depending on the relative disposition of the coupled protons (elevations that separate them, arrangement, spatial arrangement)

OH CH2 CH2 CH2 CH2 OH

(A) (B) (C)

1,4-butanediol

In the case of the molecule to study the signal at 1.36 shows a doublet, which corresponds to the hydrogen (C), is split in two for each different proton on the same carbon or on neighboring carbons.

At 3.32 ocurrs a singlet, wich belong to hidrogen (B). The last signal is a quintet, at 4.63 belonging to the hydrogen (C)

Explanation

Nuclear magnetic resonance NMR is a physical phenomenon based on the mechanical-quantum properties of atomic nuclei. NMR also refers to the family of scientific methods that explore this phenomenon to study molecules, macromolecules, as well as tissues and whole organisms.

NMR takes advantage of the fact that atomic nuclei resonate at a frequency directly proportional to the force of a magnetic field exerted, in accordance with the Larmor precession frequency equation, to subsequently disturb this alignment with the use of an alternating magnetic field, of orthogonal orientation.

The behavior of the nuclei in the magnetic field can be influenced in multiple ways, to give different types of information, but the basic information obtained is:

Frequency at which each particular nuclei comes out, displacement.
Number of nucleis of each type, integral.
Number and arrangement of nearby nuclei, multiplicity.

6 0

3 years ago

A solid piece of lead has a mass of 23.94g and a volume of 2.10cm^3. from these data, calculate the density of lead in si units

jeyben [28]

A density of a substance is constant. It is an extensive property, meaning it does not depend on the amount of substance because it is a ratio of mass to volume. No matter how much of each there is, they would always have a fixed ratio called density. For lead, the density is

Density = mass/volume
Density = 23.94 g/ 2.10 cm³
Density = 11.4 g/cm³

4 0

3 years ago

Which pair of elements below have +3 ionic change? A. Al and Ga B. Sc and Y