Astudent who stresses too much about his grades has incorrectly named an organic compound 3-propylhexane.

what is the correct name?

1.) 3-propylhexane

2.) 3-ethylhexane

3.) 4-ethylhexane

4.) 1,1-dipropylpropane

5.) none of these

6.) propane

7.) butene

8.) pentane

9.) pentene

None of these.

The correct answer should be, 4-ethylheptane.

Explanation:

In naming Alkanes, the general rules apply:

I.Identify the longest continuous carbon chain and name it as the root or parent name.

II.Identify any side chains and add their names and positions as a prefix to the parent chain.

III.When there are more than one type of side chain, name them alphabetically.

IV.Use hyphens between numbers and letters and commas between numbers.

V. Number your side chains to obtain the lowest number combinations possible.

For the above question,

first, attempt drawing only the carbon skeleton, of 3-propylhexane thus,

C-C-C-C-C-C

|

C-C-C

The longest continuous carbon chain (numbering from the top right) is 7 carbon atoms, hence, parent or root name is heptane. The 2 carbon atoms (at top left) not numbered make up the alkyl group called ethyl and since they are attached to carbon number 4 of the numbered carbon atoms ( whether the numbering is from top right to bottom right or vice versa ), their position and name should be written as a prefix to the parent name. That is why the organic compound is named, 4-ethylheptane.

Please note that in drawing the carbon skeleton of 3-propylhexane, the name is the same even if you start placing the bottom 3 carbon atoms on the 3rd carbon (top) from the left or from the right because the numbering can start from any side to achieve the lowest number combinations of numbering common Alkanes.

n2(g) + 3h2-> 2nh3(g)   this is the balanced equation

note the mole ratio between n2, h2 and nh3.   it is 1 : 3 : 2   this will be important.

moles n2 present = 28.0 g n2 x 1 mole n2/28 g = 1 mole n2 present

moles h2 present = 25.0 g h2 x 1 mole h2/2 g = 12.5 moles h2 present

based on mole ratio, n2 is limiting in this situation because there is more than enough h2 but not enough n2.

moles nh3 that can be produced = 1 mole n2 x 2 moles nh3/mole n2 = 2 moles nh3 can be produced

grams of nh3 that can be produced = 2 moles nh3 x 17 g/mole = 34 grams of nh3 can be produced

note:   the key to this problem is recognizing that n2 is limiting, and therefore limits how much nh3 can be produced.

the answer is learned