Question

question 9 (1 point)
which alkane would most likely be a liquid at room temperature?
methane
ethane
propane
butane
pentane
question 10 (1 point)
name ch₃ch(oh)ch₃.
iso - ethanol
tertiary - propanol
butan - 1 - ol
propan - 1 - ol
propan - 2 - ol

Explanation:

Question 9

Alkanes with 1 - 4 carbon atoms (methane \(CH_4\), ethane \(C_2H_6\), propane \(C_3H_8\), butane \(C_4H_{10}\)) are gases at room temperature (\(25^{\circ}C\)). Alkanes with 5 carbon atoms (pentane \(C_5H_{12}\)) and more start to be liquids at room temperature. This is because as the number of carbon atoms increases, the strength of London dispersion forces (inter - molecular forces) increases. With stronger inter - molecular forces, more energy is required to separate the molecules. So, pentane has stronger inter - molecular forces compared to methane, ethane, propane, and butane, making it a liquid at room temperature.

1. Identify the parent chain:

• The compound \(CH_3CH(OH)CH_3\) has 3 carbon atoms in the longest chain. So, the parent chain is propane.

1. Locate the functional group:

• The \(-OH\) (hydroxyl) group is on the second carbon atom.
• According to IUPAC nomenclature for alcohols, we name the compound based on the parent alkane and the position of the \(-OH\) group.
• For an alcohol with the \(-OH\) group on the second carbon of a 3 - carbon chain (\(CH_3CH(OH)CH_3\)), the name is propan - 2 - ol.
• iso - ethanol is not a valid name as ethanol has 2 carbon atoms. Tertiary - propanol is not the correct IUPAC name. Butan - 1 - ol has 4 carbon atoms. Propan - 1 - ol has the \(-OH\) group on the first carbon of the 3 - carbon chain (\(CH_3CH_2CH_2OH\)).

Answer:

pentane

Question 10