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3 years ago

Amber is a precious material used in jewelry. It forms when the resin of pine trees hardens into stone. Is amber a mineral

1 answer:

5 0

Amber is not a mineral because amber is a hardened resin of specific species of ancient trees which has been fossilized over many years.

hope this helps!

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After distilling your crude methyl benzoate, you set aside 5.12 grams of the purified ester. You then prepare the grignard reage

marysya [2.9K]

Answer:

Percent yield is 54%

Explanation:

The Grignard reaction is:

Mg + bromobenzene → phenylmagnesium bromide

Moles of Mg are:

2,3g×(1mol/24.3g) = 0.095 moles Mg.

Moles of bromobenzene are:

9,45mL×(1.495g/1mL)×(1mol/157.01g)= 0.0900 of bromobenzene.

The limiting reactant is bromobenzene. That means moles of phenylmagnesium bromide are 0.0900 moles.

To produce triphenyl carbinol you require:

2 phenylmagnesium bromide + methyl benzoate → triphenyl carbinol

Moles of methyl benzoate are:

5.12g×(1mol/136,15g) = 0.0376 moles of methyl benzoate.

The complete reaction of 0.0376 moles of methyl benzoate requires:

0.0376 moles of methyl benzoate× $\frac{2mol PhenylmagnesiumBromide}{1molMethylBenzoate}$ = 0.0752 moles of phenylmagnesium bromide. As you have 0.900 moles of phenylmagnesium bromide, limiting reagent is Methyl benzoate and moles of triphenyl carbinol are 0.0376. In grams:

0.0376 moles of triphenyl carbinol×(260.33g/mol) = 9,79g of triphenyl carbinol <em>-This is the teorethical yield- </em>

Percent yield is the ratio of actual yield to the theoretical yield. That is:

5,3g / 9,79g ×100 = <em>54%</em>

I hope it helps!

3 0

3 years ago

in a chemical change how does the total energy of the reactants compare to the total energy of the products

jeka57 [31]

Answer:

Explanation:

All chemical changes requires a substantial amount of energy. Depending on the type of reaction, the energy of reactants and products differs.

In an exothermic chemical change where heat is always given off to the surroundings, the energy of the product is less than that of reactants.

For endothermic changes, the surrounding becomes colder at the end of the reaction. This implies that the heat energy of the product is higher than that of the reactants.

8 0

3 years ago

If the reactants are 10 kg what is the mass of the products

nlexa [21]

If the mass of both the reactants is 10kg then the mass of the products also equals 10kg.

It is due to the law of conservation of mass.

Mass can neither be created nor be destroyed.

7 0

3 years ago

1. A(n)______________ bond forms when one atom gives up one or more electrons to another atom.

aalyn [17]

1. An____ionic____ bond forms when one atom gives up one or more electrons to another atom.

2. Atoms or molecules with a net electric charge due to the loss or gain of one or more electrons are ions.

3. A_covalent__bond involves the sharing of electron pairs between atoms, also known as a molecular bond. 4. When one pair of electrons is shared between two atoms, a single bond is formed. 5. When two pairs of electrons are shared between two atoms, a double bond is formed. 6. A polar covalent bond is a type of chemical bond where a pair of electrons is unequally shared between two atoms. As a result, one end of the molecule has a slightly negative charge and the other a slightly positive charge. 7. Atoms involved in a nonpolar covalent bond equally share electrons; there is no charge separation to the molecule. 8. A weak bond called a van der waals bond results from an attraction between a slightly positive region in a molecule and a slightly negative region in the same or a different molecule

3 0

4 years ago

As a person BAC level increase it becomes difficult for them to judge their vehicle distances and speed

Eddi Din [679]

Answer:

TRUE

Explanation:

The blood alcohol content is also known as the blood alcohol level or the blood alcohol concentration. It is defined as the measurement of the alcohol intoxication in the body and is used for the legal or the medical purposes.

When the BAC increases in the person's body, the person started to loose clear vision, loss of short term memory, poor muscle coordination, impaired perception and face difficulty in concentrating. Thus it becomes very difficult for a person to drive a car or ride a bike whose BAC has increased.

The driver cannot properly judge the distances between the vehicle and the speed of the vehicle.

Hence the answer is TRUE.

8 0

3 years ago