Question 1

Alkanes are characterized by the general molecular formula:

Accepted Answer

Alkanes are saturated hydrocarbons with the general molecular formula $\mathrm{C}_{n} \mathrm{H}_{2n+2}$, where $n$ is the number of carbon atoms.

Question 2

Cycloalkanes are characterized by the general molecular formula:

Accepted Answer

Cycloalkanes have the general molecular formula $\mathrm{C}_{n} \mathrm{H}_{2n}$, which reflects that they have two hydrogen atoms less than the corresponding alkanes ($\mathrm{C}_{n} \mathrm{H}_{2n+2}$) due to the ring structure forming a closed loop.

Question 3

The carbon-carbon sigma bond in ethane is formed by overlap of which two orbitals?

Accepted Answer

The carbon atoms in ethane are sp3 hybridized, and the sigma bond between them is formed by the head-on overlap of two sp3 hybrid orbitals.

Question 4

What is the IUPAC name of the following?

Accepted Answer

The answer of What is the IUPAC name of the...

Question 5

The $\mathrm{C}-\mathrm{C}$ sigma bond in acetylene is formed by the overlap of which two orbitals?
$\mathrm{H}-\mathrm{C} \equiv \mathrm{C}-\mathrm{H}$

Accepted Answer

The $\mathrm{C}-\mathrm{C}$ sigma bond in acetylene is formed by the overlap of $sp-sp$ orbitals, as each carbon atom in acetylene is $sp$ hybridized to form a sigma bond, with the remaining orbitals forming pi bonds.

Question 6

Which of the following are constitutional isomers?

Accepted Answer

The answer of Which of the following are constitutional isomers?

...

Question 7

Arrange the following isomeric alkanes in order of increasing boiling point.
I. $n$-heptane
II. 2,3-dimethylpentane
III. 2,2,3-trimethylbutane

Accepted Answer

Boiling points of alkanes generally increase with molecular size and decrease with branching. Among the given isomers, 2,2,3-trimethylbutane is the most branched, followed by 2,3-dimethylpentane, and $n$-heptane is a straight chain. Therefore, the boiling point increases from the most branched to the least branched: III $<$ II $<$ I.

Question 8

Which of the following has(have) a higher oxidation state of carbon than the carbon in formaldehyde, $\mathrm{H}_{2} \mathrm{C}=\mathrm{O}$ ?
I. $\mathrm{CH}_{3} \mathrm{OH}$
II. $\mathrm{HCO}_{2} \mathrm{H}$
III. $\mathrm{H}_{2} \mathrm{CO}_{3}$

Accepted Answer

In formaldehyde ($\mathrm{H}_{2}C=O$), carbon has an oxidation state of +2. In $\mathrm{CH}_{3}OH$, carbon's oxidation state is -2, which is lower. In $\mathrm{HCO}_{2}H$ (formic acid), carbon's oxidation state is +2, and in $\mathrm{H}_{2}\mathrm{CO}_{3}$ (carbonic acid), it is +4. Therefore, both formic acid and carbonic acid have carbon in a higher oxidation state than in formaldehyde.

Question 9

Carbon atoms 1,2 , and 3 in the following structure are classified, respectively, as

Accepted Answer

The answer of Carbon atoms 1,2 , and 3 in...

Question 10

The heats of combustion $\left(-\Delta H^{\circ}\right)$ of heptane and 3,3-dimethypentane are 4,817 and $4,809 \mathrm{~kJ} / \mathrm{mol}$, respectively. Which statement is true?

Accepted Answer

The lower the heat of combustion ($-\Delta H^{\circ}$), the more stable the compound. Since 3,3-dimethylpentane has a slightly lower heat of combustion than heptane, it is considered more stable by $8 \mathrm{~kJ} / \mathrm{mol}$.

Question 11

The reaction of acetylene with hydrogen gas is shown below. Which statements are true concerning the reaction?
$$\mathrm{H}-\mathrm{C} \equiv \mathrm{C}-\mathrm{H}+2 \mathrm{H}_{2} \xrightarrow{\mathrm{Pd} \text { (cat.) }} \mathrm{H}_{3} \mathrm{C}-\mathrm{CH}_{3}$$
I. Acetylene is oxidized to ethane.
II. Acetylene is reduced to ethane.
III. Carbon changes oxidation state from -1 to -3 .
IV. Hydrogen (from $\mathrm{H}_{2}$ ) changes oxidation state from 0 to +1 .

Accepted Answer

Acetylene is reduced to ethane because hydrogen is added to it. The oxidation state of carbon in acetylene (C2H2) changes from -1 in each carbon to -3 in ethane (C2H6), indicating reduction. Hydrogen's oxidation state does not change to +1 upon addition to a molecule; it remains at 0 in H2 and is considered -1 in hydrocarbons like ethane.

Question 12

How many moles of $\mathrm{O}_{2}$ gas would be consumed in the complete combustion of 0.100 mole of $\mathrm{C}_{5} \mathrm{H}_{12}$ ?

Accepted Answer

The complete combustion of pentane ($\mathrm{C}_{5} \mathrm{H}_{12}$) can be represented by the balanced chemical equation: $\mathrm{C}_{5} \mathrm{H}_{12} + 8\mathrm{O}_{2} \rightarrow 5\mathrm{CO}_{2} + 6\mathrm{H}_{2}\mathrm{O}$. This shows that 1 mole of $\mathrm{C}_{5} \mathrm{H}_{12}$ requires 8 moles of $\mathrm{O}_{2}$ for complete combustion. Therefore, 0.100 mole of $\mathrm{C}_{5} \mathrm{H}_{12}$ would consume 0.800 mole of $\mathrm{O}_{2}$.

Question 13

What is the relationship between the two structures below?

Accepted Answer

The answer of What is the relationship between the two...

Question 14

What is the IUPAC name of the following structure?

Accepted Answer

The answer of What is the IUPAC name of the...

Question 15

What is the estimated $\mathrm{C}-\mathrm{C}-\mathrm{C}$ bond angle in the following structure?

Accepted Answer

The answer of What is the estimated $\mathrm{C}-\mathrm{C}-\mathrm{C}$ bond angle...

Question 16

The $\mathrm{sp}^{3}$ orbitals of carbon in $\mathrm{CH}_{4}$ are formed from the

Accepted Answer

The $\mathrm{sp}^{3}$ hybrid orbitals in methane ($\mathrm{CH}_{4}$) are formed by the hybridization of the $2s$ orbital and all three $2p$ orbitals of carbon.

Question 17

What is the $\mathrm{Cl}-\mathrm{C}-\mathrm{Cl}$ bond angle in $\mathrm{CCl}_{4}$ ?

Accepted Answer

The molecule $\mathrm{CCl}_{4}$ has a tetrahedral geometry, which results in a $\mathrm{Cl}-\mathrm{C}-\mathrm{Cl}$ bond angle of $109.5^{\circ}$.

Question 18

The carbon-carbon single bond in the following is formed by the overlap of which two orbitals?
$\mathrm{H}_{2} \mathrm{C}=\mathrm{CH}-\mathrm{C} \equiv \mathrm{N}$

Accepted Answer

The carbon in the double bond ($=$) is $sp^2$ hybridized, and the carbon in the triple bond ($\equiv$) is $sp$ hybridized. Therefore, the carbon-carbon single bond between them is formed by the overlap of an $sp^2$ orbital from the double-bonded carbon and an $sp$ orbital from the triple-bonded carbon.

Quiz 2: Alkanes and Cycloakanes: Introduction to Hydrocarbons

Alkanes are characterized by the general molecular formula:

Cycloalkanes are characterized by the general molecular formula:

The carbon-carbon sigma bond in ethane is formed by overlap of which two orbitals?

What is the IUPAC name of the following?

The $\mathrm{C}-\mathrm{C}$ sigma bond in acetylene is formed by the overlap of which two orbitals? $\mathrm{H}-\mathrm{C} \equiv \mathrm{C}-\mathrm{H}$

Which of the following are constitutional isomers?

Arrange the following isomeric alkanes in order of increasing boiling point. I. $n$ -heptane II. 2,3-dimethylpentane III. 2,2,3-trimethylbutane

Which of the following has(have) a higher oxidation state of carbon than the carbon in formaldehyde, $\mathrm{H}_{2} \mathrm{C}=\mathrm{O}$ ? I. $\mathrm{CH}_{3} \mathrm{OH}$ II. $\mathrm{HCO}_{2} \mathrm{H}$ III. $\mathrm{H}_{2} \mathrm{CO}_{3}$

Carbon atoms 1,2 , and 3 in the following structure are classified, respectively, as

The heats of combustion $\left(-\Delta H^{\circ}\right)$ of heptane and 3,3-dimethypentane are 4,817 and $4,809 \mathrm{~kJ} / \mathrm{mol}$ , respectively. Which statement is true?

How many moles of $\mathrm{O}_{2}$ gas would be consumed in the complete combustion of 0.100 mole of $\mathrm{C}_{5} \mathrm{H}_{12}$ ?

What is the relationship between the two structures below?

What is the IUPAC name of the following structure?

What is the estimated $\mathrm{C}-\mathrm{C}-\mathrm{C}$ bond angle in the following structure? $What is the estimated \mathrm{C}-\mathrm{C}-\mathrm{C} bond angle in the following structure? A) 90^{\circ} B) 109.5^{\circ} C) 120^{\circ} D) 180^{\circ}$

The $\mathrm{sp}^{3}$ orbitals of carbon in $\mathrm{CH}_{4}$ are formed from the

What is the $\mathrm{Cl}-\mathrm{C}-\mathrm{Cl}$ bond angle in $\mathrm{CCl}_{4}$ ?

The carbon-carbon single bond in the following is formed by the overlap of which two orbitals? $\mathrm{H}_{2} \mathrm{C}=\mathrm{CH}-\mathrm{C} \equiv \mathrm{N}$

Quiz 2: Alkanes and Cycloakanes: Introduction to Hydrocarbons

Alkanes are characterized by the general molecular formula:

Cycloalkanes are characterized by the general molecular formula:

The carbon-carbon sigma bond in ethane is formed by overlap of which two orbitals?

What is the IUPAC name of the following?

The C−C\mathrm{C}-\mathrm{C}C−C sigma bond in acetylene is formed by the overlap of which two orbitals? H−C≡C−H\mathrm{H}-\mathrm{C} \equiv \mathrm{C}-\mathrm{H}H−C≡C−H

Which of the following are constitutional isomers?

Arrange the following isomeric alkanes in order of increasing boiling point. I. nnn -heptane II. 2,3-dimethylpentane III. 2,2,3-trimethylbutane

Which of the following has(have) a higher oxidation state of carbon than the carbon in formaldehyde, H2C=O\mathrm{H}_{2} \mathrm{C}=\mathrm{O}H2​C=O ? I. CH3OH\mathrm{CH}_{3} \mathrm{OH}CH3​OH II. HCO2H\mathrm{HCO}_{2} \mathrm{H}HCO2​H III. H2CO3\mathrm{H}_{2} \mathrm{CO}_{3}H2​CO3​

Carbon atoms 1,2 , and 3 in the following structure are classified, respectively, as

The heats of combustion (−ΔH∘) \left(-\Delta H^{\circ}\right) (−ΔH∘) of heptane and 3,3-dimethypentane are 4,817 and 4,809 kJ/mol4,809 \mathrm{~kJ} / \mathrm{mol}4,809 kJ/mol , respectively. Which statement is true?

How many moles of O2\mathrm{O}_{2}O2​ gas would be consumed in the complete combustion of 0.100 mole of C5H12\mathrm{C}_{5} \mathrm{H}_{12}C5​H12​ ?

What is the relationship between the two structures below?

What is the IUPAC name of the following structure?

What is the estimated C−C−C\mathrm{C}-\mathrm{C}-\mathrm{C}C−C−C bond angle in the following structure?

The sp3\mathrm{sp}^{3}sp3 orbitals of carbon in CH4\mathrm{CH}_{4}CH4​ are formed from the

What is the Cl−C−Cl\mathrm{Cl}-\mathrm{C}-\mathrm{Cl}Cl−C−Cl bond angle in CCl4\mathrm{CCl}_{4}CCl4​ ?

The carbon-carbon single bond in the following is formed by the overlap of which two orbitals? H2C=CH−C≡N\mathrm{H}_{2} \mathrm{C}=\mathrm{CH}-\mathrm{C} \equiv \mathrm{N}H2​C=CH−C≡N

The $\mathrm{C}-\mathrm{C}$ sigma bond in acetylene is formed by the overlap of which two orbitals? $\mathrm{H}-\mathrm{C} \equiv \mathrm{C}-\mathrm{H}$

Arrange the following isomeric alkanes in order of increasing boiling point. I. $n$ -heptane II. 2,3-dimethylpentane III. 2,2,3-trimethylbutane

Which of the following has(have) a higher oxidation state of carbon than the carbon in formaldehyde, $\mathrm{H}_{2} \mathrm{C}=\mathrm{O}$ ? I. $\mathrm{CH}_{3} \mathrm{OH}$ II. $\mathrm{HCO}_{2} \mathrm{H}$ III. $\mathrm{H}_{2} \mathrm{CO}_{3}$

The heats of combustion $\left(-\Delta H^{\circ}\right)$ of heptane and 3,3-dimethypentane are 4,817 and $4,809 \mathrm{~kJ} / \mathrm{mol}$ , respectively. Which statement is true?

How many moles of $\mathrm{O}_{2}$ gas would be consumed in the complete combustion of 0.100 mole of $\mathrm{C}_{5} \mathrm{H}_{12}$ ?

What is the estimated $\mathrm{C}-\mathrm{C}-\mathrm{C}$ bond angle in the following structure? $What is the estimated \mathrm{C}-\mathrm{C}-\mathrm{C} bond angle in the following structure? A) 90^{\circ} B) 109.5^{\circ} C) 120^{\circ} D) 180^{\circ}$

The $\mathrm{sp}^{3}$ orbitals of carbon in $\mathrm{CH}_{4}$ are formed from the

What is the $\mathrm{Cl}-\mathrm{C}-\mathrm{Cl}$ bond angle in $\mathrm{CCl}_{4}$ ?

The carbon-carbon single bond in the following is formed by the overlap of which two orbitals? $\mathrm{H}_{2} \mathrm{C}=\mathrm{CH}-\mathrm{C} \equiv \mathrm{N}$