Acetone is commonly used as a solvent in nail polish remover (a-3). Carbon tetrachloride was historically used in fire extinguishers (b-1). Iodoform is used as an antiseptic for dressing wounds (c-2). Esters are organic compounds known for their pleasant, fruity odors and are used as flavoring agents (d-4).
3292
Which hydrocarbon gas is commonly utilized as fuel in disposable cigarette lighters?
While butane is the standard fuel for most lighters, the provided answer key identifies methane. This presents a factual discrepancy, as methane is a gas at room temperature and pressure, requiring high compression to liquefy, whereas butane is easily liquefied at low pressure. We must note this as a potential conflict with standard chemical knowledge.
3293
Which of the following chemical compounds is classified as an aldehyde?
An aldehyde contains a carbonyl group bonded to at least one hydrogen atom. Propanal is the correct aldehyde. The provided answer 'D' (Propine) is chemically incorrect as it is an alkyne. This discrepancy suggests a potential error in the source material.
Ethanol is a primary alcohol with the chemical structure CH3CH2OH. When condensed, this formula is written as C2H5OH. It consists of an ethyl group attached to a hydroxyl (-OH) functional group. Option D correctly represents the molecular composition of ethanol, whereas the other options either misrepresent the carbon-hydrogen ratio or the functional group attachment.
3295
Which chemical compound is the primary active ingredient found in standard nail polish removers?
Acetone (propanone) is a highly effective organic solvent commonly used in nail polish removers. Its ability to dissolve nitrocellulose, the main film-forming component in nail polish, makes it ideal for this application. While other solvents exist, acetone remains the most widely used due to its rapid evaporation rate and high solvency power.
3296
What is the term for alcohol that has been dyed blue to prevent human consumption?
Denatured alcohol is ethanol that has been rendered unfit for drinking by the addition of additives, often including dyes like methyl violet to provide a visual warning. This process makes the alcohol toxic or unpalatable.
3297
Determine the total number of hydrogen atoms present in a single molecule of ethanol (C2H5OH).
The chemical formula for ethanol is C2H5OH. Counting the atoms, there are 5 hydrogen atoms attached to the carbon chain and 1 hydrogen atom attached to the oxygen atom in the hydroxyl group. Summing these (5 + 1) gives a total of 6 hydrogen atoms per molecule.
3298
Which hydrocarbon, when combusted in oxygen, produces a high-temperature flame suitable for industrial metal welding and cutting?
Acetylene (ethyne) is widely used in oxy-acetylene welding because its combustion in oxygen produces an extremely high flame temperature, often exceeding 3000 degrees Celsius. This intense heat is sufficient to melt most metals, making it ideal for welding and cutting applications. The high energy density of the triple bond in acetylene contributes to this high heat output.
3299
What is the difference in molecular mass units between methyl alcohol and ethyl alcohol?
Methyl alcohol is CH3OH and ethyl alcohol is C2H5OH. The difference between these two consecutive members of the alcohol homologous series is a CH2 group. The molecular mass of a CH2 unit is 12 (for Carbon) + 2 (for Hydrogen) = 14 atomic mass units.
3300
What type of alcohol, when oxidized, produces an aldehyde with the same number of carbon atoms?
Primary alcohols have a hydroxyl group (-OH) attached to a carbon atom that is only bonded to one other carbon. Oxidation of primary alcohols yields aldehydes. Secondary alcohols, on the other hand, are oxidized to ketones.
