18.The average or small size stars become a ________

An alkane with the formula C6H14 can be prepared by hydrogenation of either of two precursor alkenes having the formula C6H12.

ankoles [38]

Two precursor alkenes

H₃C CH₃
I I
H₂C=C-CH-CH₃ 2,3-dimethyl-1-butene

H₃C   CH₃
I   I
H₃C-CH=CH-CH₃ 2,3-dimethyl-2-butene

alkane

H₃C CH₃
  I I
H₃C-CH-CH-CH₃ 2,3-dimethylbutane

H₃C  CH₃ H₃C CH₃
I   I I I
H₂C=C-CH-CH₃ + H₂ → H₃C-CH-CH-CH₃

H₃C CH₃ H₃C   CH₃
I    I     I I
H₂C-C=CH-CH₃ + H₂ → H₃C-CH-CH-CH₃

6 0

3 years ago

Read 2 more answers

You mix 285.0 mL of 1.20 M lead(II) nitrate with 300.0 mL of 1.60 M potassium iodide. The lead(II) iodide is insoluble. Which of

SIZIF [17.4K]

Answer:

D. The final concentration of NO3– is 0.821 M.

Explanation:

Considering:

$Molarity=\frac{Moles\ of\ solute}{Volume\ of\ the\ solution}$

Or,

$Moles =Molarity \times {Volume\ of\ the\ solution}$

Given :

For potassium iodide :

Molarity = 1.60 M

Volume = 300.0 mL

The conversion of mL to L is shown below:

1 mL = 10⁻³ L

Thus, volume = 300.0×10⁻³ L

Thus, moles of potassium iodide :

$Moles=1.60 \times {300.0\times 10^{-3}}\ moles$

Moles of potassium iodide = 0.48 moles

For lead(II) nitrate :

Molarity = 1.20 M

Volume = 285 mL

The conversion of mL to L is shown below:

1 mL = 10⁻³ L

Thus, volume = 285×10⁻³ L

Thus, moles of lead(II) nitrate :

$Moles=1.20\times {285\times 10^{-3}}\ moles$

Moles of lead(II) nitrate = 0.342 moles

According to the given reaction:

$2KI_{(aq)}+Pb(NO_3)_2_{(aq)}\rightarrow PbI_2_{(s)}+2KNO_3_{(aq)}$

2 moles of potassium iodide react with 1 mole of lead(II) nitrate

1 mole of potassium iodide react with 1/2 mole of lead(II) nitrate

0.48 moles potassium iodide react with 0.48/2 mole of lead(II) nitrate

Moles of lead(II) nitrate = 0.24 moles

Available moles of lead(II) nitrate = 0.342 moles

Limiting reagent is the one which is present in small amount. Thus, potassium iodide is limiting reagent.

Also, consumed lead(II) nitrate = 0.24 moles (lead ions precipitate with iodide ions)

Left over moles = 0.342 - 0.24 moles = 0.102 moles

Total volume = 300 + 285 mL = 585 mL = 0.585 L

So, Concentration = 0.102/0.585 M = 1.174 M

Statement A is correct.

The formation of the product is governed by the limiting reagent. So,

2 moles of potassium iodide gives 1 mole of lead(II) iodide

1 mole of potassium iodide gives 1/2 mole of lead(II) iodide

0.48 mole of potassium iodide gives 0.48/2 mole of lead(II) iodide

Mole of lead(II) iodide = 0.24 moles

Molar mass of lead(II) iodide = 461.01 g/mol

Mass of lead(II) chloride = Moles × Molar mass = 0.24 × 461.01 g = 111 g

Statement B is correct.

Potassium iodide is the limiting reagent. So all the potassium ion is with potassium nitrate . Thus,

2 moles of Potassium iodide on reaction forms 2 moles of potassium ion

0.48 moles of Potassium iodide on reaction forms 0.48 moles of potassium ion

Total volume = 300 + 285 mL = 585 mL = 0.585 L

So, Concentration = 0.48/0.585 M = 0.821 M

Statement C is correct.

Nitrate ions are furnished by lead(II) nitrate . So,

1 mole of lead(II) nitrate produces 2 moles of nitrate ions

0.342 mole of lead(II) nitrate produces 2*0.342 moles of nitrate ions

Moles of nitrate ions = 0.684 moles

So, Concentration = 0.684/0.585 M = 1.169 M

Statement D is incorrect.

4 0

3 years ago

When two atoms form a covalent bond, they share electrons from all of their orbitals. All of their orbitals, in turn, combine to

erma4kov [3.2K]

Answer:

It's false.

Explanation:

Molecular orbital theory states that the number of molecular orbitals is equal to the number of atomic orbitals that overlap. The lowest energy molecular orbital is formed when two atomic orbitals that are in phase overlap, forming a bonding molecular orbital. However, another molecular orbital is also formed, called an anti-binding orbital.

So if an "n" quantity of atomic orbitals is combined, an "n" quantity of molecular orbitals is formed.

Have a nice day!

8 0

4 years ago

How many molecules are in 3.2 mol of ammonia,NH3

EastWind [94]

Here we are talking about ammonia which is a molecule. Now 1 mole of ammonia also contains 6.022 * 10^23 molecules of ammonia. In one molecule of ammonia,we have 1 nitrogen atom and 3 hydrogen atom.

5 0

3 years ago

Which career is most concerned with the study of radioactive isotopes? biochemistnuclear chemistorganic chemistnuclear engineer

Andreyy89

Nuclear chemist is most concerned with the study of radioactive isotopes.

<h3>What is radioactive isotopes?</h3>

A chemical element in an unstable state that emits radiation as it decomposes and becomes more stable.
Radioisotopes can be created in a lab or in the natural world. They are utilized in imaging studies and therapy in medicine. likewise known as radionuclide.

For instance, soil and rocks contain naturally occurring radioactive isotopes of the elements Radium, Thorium, and Uranium.
Water also contains trace levels of uranium and thorium. Air contains radon, which is a byproduct of radium's radioactive disintegration.

There are 254 stable isotopes, although there are more than 3,000 radioisotopes, only roughly 84 of which are found in nature.

Learn more about radioisotopes here:

brainly.com/question/13076859

#SPJ4

8 0

2 years ago

18.The average or small size stars become a _________ at the end of their life cycle.