Would you classify silicone as a element or compound

Determine if each of the following statements about chiral molecules is True or False and select the best answer from the dropdo

oee [108]

Answer:

See explanation

Explanation:

-) True or False: All R stereocenters are dextrorotatory.

The absolute configuration is based is in specific rules that are not related to the ability to deflect polarized light. FALSE

-) True or False: Chiral centers in organic molecules will have 4 different groups attached to a carbon.

A chiral carbon by definition is a carbon with 4 groups. TRUE

-) True or False: A racemic mixture has an optical activity of 0.

In a racemic mixture, we have equal amounts of enantiomers, and this cancels out the optical activity. TRUE

-) True or False: Normal linear amines can be chiral centers.

In primary amines, we have 2 hydrogens. Therefore all the groups can not be different. So, is TRUE

-)True or False: Compound C has an optical activity of 0.

We need to know the structure of the compound

-)True or False: If the R isomer of a molecule has an optical rotation of + 25.7 degree then the S isomer of the molecule will have an optical rotation of -25.7 degree.

If we have the exact opposite (as we have in this case) the magnitud of the optical activity value will remain and the sign will change. TRUE

-)True or False: A CN is a higher priority than a CH2OH.

In this case, a carbon is directly bonded to the chiral carbon. The carbon on CN is bonded to a nitrogen atom and the carbon on CH2OH is bonded to an oxygen. So, the CH2OH will have more priority because O has a higher atomic number. FALSE

-)True or False: All molecules with chiral centers are optically active.

We can have for example mesocompounds in which the optical activity is canceled out due to symmetry planes. FALSE

-)True or False: To have an enantiomer a molecule must have at least two chiral centers.

A pair of enantiomers is made between at least 1 chiral carbon. Enantiomer R and enantiomer S. FALSE

-)True or False: Chiral molecules are always optically active.

We can have racemic mixtures or mesocompounds with chiral carbons but without optical activity. FALSE

-)True or False: A CH2CH2Br is higher priority than a CH2F.

The "Br" atom is bonded in the third carbon (respect to the chiral carbon) and the "F" atom is bonded to the second carbon. Therefore CH2F has more priority than CH2CH2Br. FALSE

-)True or False: Meso molecules with two stereocenters have a R,S configuration.

On the compounds with R and S configuration at the same time can have symmetry planes so, we will not have optical activity. TRUE

True or False: Diastereomers have the same physical properties except in a chiral environment.

All diastereomers have the same physical properties. TRUE

True or False: Compound H has an optical activity of 0.

We have to have the structure of the compound.

True or False: A C=C double bond is higher priority than a -CH(CH3)2.

In the case of C=C, we can say that is equivalent to two carbon bonds without hydrogens. Therefore C=C has higher priority. TRUE

6 0

4 years ago

What is the net ionic equation for the following? :)

I am Lyosha [343]

Answer:

1. Mg (s) + 2Na+(aq) → 2Na(s) + Mg²⁺(aq)

2. 2K(s) + Cd²⁺(aq) → 2K⁺(aq) + Cd(s)

Explanation:

The net ionic equation of a reaction express only the chemical species that are involved in the reaction:

1. Mg (s) + Na2CrO4 (aq) → 2Na + MgCrO4(aq)

The ionic equation:

Mg (s) + 2Na+(aq) + CrO4²⁻ (aq) → 2Na + Mg²⁺ + CrO4²⁻(aq)

Subtracting the ions that don't change:

2. 2K(s) + Cd(NO3)2(aq) → 2KNO3(aq) + Cd(s)

The ionic equation:

2K(s) + Cd²⁺(aq) + 2NO3⁻(aq) → 2K⁺(aq) + 2NO3⁻(aq) + Cd(s)

Subtracting the ions that don't change:

3 0

3 years ago

A chemist wants to calculate the amount of heat that is absorbed by a sample of copper as it is melted. Which constant should sh

34kurt

The constant used for the absorption of heat by the sample in melting is $+\Delta H_{fus}$ . Thus, option A is correct.

The chemical reaction has been defined as the energy in which the energy has been released or absorbed for the breaking of bonds in the reactants and the formation of product.

<h3>Constant for energy absorbed</h3>

The energy has been absorbed in the melting of the copper sample. Thus, the sample has been converted from the solid to the liquid state.

The change in energy with the conversion in solid and liquid state has been termed as heat of fusion.

The energy has been absorbed by the system, thus it has been marked with the positive sign.

Therefore, $+\Delta H_{fus}$ has been the constant used for the absorption of heat by the sample in melting. Thus, option A is correct.

Learn more about melting sample, here:

brainly.com/question/8828503

8 0

3 years ago

When zinc or aluminum was allowed to react with the copper sulfate , what was the limiting reagen?

musickatia [10]

Usually it is the CuSO4 that is the limiting reagent.

if all of the color of the solution was gone, but there was still some zinc metal mixed in with the copper metal produced, then Zn is the excess reagent 

f all of the color of the solution was not gone, but there was no zinc metal left in with the blue copper solution , then Zn is the limiting reagent Hope this helps.

5 0

4 years ago

What was the purpose of putting distilled water in the blank cuvette? if your unknown used ethanol as the base solvent, what wou

Margaret [11]

The purpose of using distilled water in the cuvette of the spectrophotometer is to calibrate the instrument. It is generally considered that distilled water shows zero absorbance and 100 % transmittance. So, to zero out the absorbance of compounds other than the analyte being determined, distilled water is used as a blank.

If the unknown being determined is prepared using ethanol as the base solution, the blank used must be ethanol. This is because absorbance if any from the solvent, ethanol must be zeroed out as when the measurement of the actual unknown is being made, the absorbance of the solvent does not interfere.

7 0

3 years ago