Remember what the equation is:

What is the density of a 5 mL sample of 1.95g of Gold

insens350 [35]

Answer:

density=mass/volume

=1.95/5 = 0.39 g(mL)-¹

7 0

3 years ago

You are running a rather large scale reaction where you prepare the grignard reagent phenylmagnesium bromide by reacting 210.14

almond37 [142]

Answer:

We would expect to form 7.35 moles of grignard reagent.

Explanation:

Step 1: Data given

Mass of magnesium = 210.14 grams

Volume bromobenzene = 772 mL

Density of bromobenzene = 1.495 g/mL

Molar mass of Mg = 24.3 g/mol

Molar mass of bromobenzene = 157.01 g/mol

Step 2: The balanced equation

C6H5Br + Mg ⇒ C6H5MgBr

Step 3: Calculate mass of bromobenzene

Mass bromobenzene = density bromobenzene * volume

Mass bromobenzene = 1.495 g/mL * 772 mL

Mass bromobenzene = 1154.14 grams

Step 4: Calculate number of moles bromobenzene

Moles bromobenzene = mass bromobenzene / molar mass bromobenzene

Moles bromobenzene = 1154.14g / 157.01 g/mol

Moles bromobenzene = 7.35 moles

Step 5: Calculate moles of Mg

Moles Mg = 210.14 grams /24.3 g/mol

Moles Mg = 8.65 moles

Step 6: The limiting reactant

The mole ratio is 1:1 So the bromobenzene has the smallest amount of moles, so it's the limiting reactant. It will be completely consumed ( 7.35 moles). Magnesium is in excess, There will react 7.35 moles. There will remain 8.65 - 7.35 = 1.30 moles

Step 7: Calculate moles of phenylmagnesium bromide

For 1 mole of bromobenzene, we need 1 mole of Mg to produce 1 mole of phenylmagnesium bromide

For 7.35 moles bromobenzene, we have 7.35 moles phenylmagnesium bromide

We would expect to form 7.35 moles of grignard reagent.

5 0

3 years ago

What holds strands of peptidoglycan together??

Amiraneli [1.4K]

What holds a peptidoglycan together is NAM and NAG sugars+ different amino acids.

6 0

3 years ago

Which of the following statements is not correct?

Pavlova-9 [17]

Answer: This option is incorrect: B. Covalent compounds are held together by much stronger interparticle forces than are ionic compounds.

Justification:

Ionic bonds, held by ionic compounds, are much stronger than covalent bonds, held by covalent compounds.

In ionic bonds one element yields one or more electrons forming a cation (a positively charged ion) and the other element accepts the electrons forming an anion (a negatively charged ion).

The anion and the cation are electrostatically atracted by each other. This electrostatic atraction force, named ionic bond, is very strong.

As result of this, the ionic compounds form strong crystals with high boiling and fusion points. A good example of this the sodium chloride, formed by the union of cation Na(+) and anion Cl(-).

The covalent bonds are result of sharing electrons and do not form ions. This bond is weaker than the ionic bond.

4 0

3 years ago

What is an example of how to supply activation energy to begin reaction

Sergio039 [100]

Heating the reaction flask on a hot plate is an example of supplying activation energy to begin a reaction.

Explanation:

Definition:

Activation energy is defined as the minimum amount of energy required to start a particular chemical reaction.

For example: When hydrogen and oxygen are mixed together it does not immediately start the reaction to form water. So, to start the reaction a small electric spark is provided or it is heated to provide some energy. This energy causes the molecules of hydrogen and water to react, thus producing even more molecules to react and finally water is formed.

Here the electric spark or the heat provided is the activation energy.

5 0

3 years ago