1.
What are produced when ethanol is burns completely in air?
Correct Answer
C. Carbon dioxide and water
Explanation
When ethanol burns completely in air, it undergoes a combustion reaction. This reaction involves the complete oxidation of ethanol, resulting in the formation of carbon dioxide (CO2) and water (H2O). Therefore, the correct answer is carbon dioxide and water.
2.
Which is false about the formation of ethanol?
Correct Answer
A. Ethanol is produced through the hydration of ethane
Explanation
Ethanol is not produced through the hydration of ethane. Ethanol is primarily produced through the fermentation of sugars by yeast or bacteria. During this process, the sugars are converted into ethanol and carbon dioxide. The hydration of ethene, not ethane, can also produce ethanol. Ethane, on the other hand, is a hydrocarbon and does not directly produce ethanol through hydration.
3.
What is the general molecular formula of alcohol?
Correct Answer
A. CnH2n+1OH
Explanation
The general molecular formula of alcohol is CnH2n+1OH. This formula represents the structure of alcohol molecules, where "n" represents the number of carbon atoms in the molecule. The "Cn" part indicates the presence of a carbon chain, the "H2n+1" part represents the number of hydrogen atoms attached to the carbon chain, and the "OH" part indicates the presence of a hydroxyl group (-OH) attached to one of the carbon atoms in the chain. This formula applies to all types of alcohols, including methanol, ethanol, and propanol.
4.
What is the reaction between an alcohol and carboxylic acid called?
Correct Answer
C. Esterification
Explanation
Esterification is the reaction between an alcohol and a carboxylic acid. In this reaction, the -OH group of the alcohol reacts with the -COOH group of the carboxylic acid, resulting in the formation of an ester and water as a byproduct. This reaction is commonly used in the production of esters, which have various applications in industries such as fragrance, flavor, and pharmaceuticals.
5.
What are the conditions for dehydration of alcohols?
Correct Answer
B. Concentrated sulfuric acid as dehydrating agent and temperature at 180 degrees celsius
Explanation
The conditions for dehydration of alcohols involve the use of a dehydrating agent and specific temperature. In this case, the correct answer is concentrated sulfuric acid as the dehydrating agent and a temperature of 180 degrees Celsius. Sulfuric acid is a strong acid that can remove water molecules from alcohol, resulting in the formation of an alkene. The high temperature helps to facilitate the removal of water molecules and promote the dehydration reaction.
6.
What are alcohols not used in?
Correct Answer
C. Plastics
Explanation
Alcohols are used in many industries and products, including wine, vinegar, and methylated spirits. However, they are not commonly used in the production of plastics. Plastics are typically made from polymers, which are large molecules formed by the repetition of smaller units. While some plastics may contain small amounts of alcohol as a solvent or additive, alcohols themselves are not a primary component in the production of plastics.
7.
Vinegar tastes sour because of ______.
Correct Answer
A. Ethanoic acid
Explanation
Vinegar tastes sour because it contains ethanoic acid. Ethanoic acid, also known as acetic acid, is a weak acid that gives vinegar its characteristic sour taste. When ethanoic acid is dissolved in water, it releases hydrogen ions, which stimulate sour taste receptors on the tongue, resulting in the sour taste sensation. Ethanol, butanoic acid, and ethyl ethanoate are other compounds that can be found in vinegar, but they do not contribute to its sour taste.
8.
Esterification is a __________.
Correct Answer
A. Condensation reaction
Explanation
Esterification is a condensation reaction because it involves the formation of an ester by the combination of an alcohol and an organic acid. In this reaction, a water molecule is eliminated, resulting in the formation of the ester. Condensation reactions typically involve the loss of a small molecule, such as water or alcohol, and the formation of a larger molecule.
9.
What is true about carboxylic acids?
Correct Answer
B. Carboxylic acids can react with metals
Explanation
Carboxylic acids can react with metals. This is because carboxylic acids have a carboxyl group (-COOH) which contains both a carbonyl group (C=O) and a hydroxyl group (OH). The carbonyl group can react with metals to form metal carboxylates, while the hydroxyl group can dissociate to release a hydrogen ion, making carboxylic acids acidic. The reaction with metals typically involves the displacement of hydrogen from the carboxyl group by the metal.
10.
What are the products of the reaction between methanol and ethanoic acid
Correct Answer
C. Methyl ethanoate and water
Explanation
The reaction between methanol and ethanoic acid produces methyl ethanoate and water. Methanol (CH3OH) reacts with ethanoic acid (CH3COOH) to form methyl ethanoate (CH3COOCH3) and water (H2O). This reaction is known as esterification, where an alcohol reacts with an acid to form an ester and water.
11.
Which is true about ethanoic acid?
Correct Answer
A. It has a higher boiling point than ethanol
Explanation
Ethanoic acid has a higher boiling point than ethanol because it forms stronger intermolecular forces due to the presence of the carboxyl group (-COOH). The carboxyl group allows for hydrogen bonding between ethanoic acid molecules, which requires more energy to break and results in a higher boiling point compared to ethanol. Ethanol, on the other hand, can only form weaker intermolecular forces through hydrogen bonding with the hydroxyl group (-OH), leading to a lower boiling point.
12.
Esters are ________.
Correct Answer
B. Used to make perfumes and flavourings
Explanation
Esters are organic compounds that are commonly used in the production of perfumes and flavorings. They are formed through the reaction between alcohols and organic acids. Esters are known for their pleasant and distinct aromas, which make them ideal for adding scent and flavor to various products. They are not poisonous and are not necessarily foul-smelling compounds, as their odor can vary depending on the specific ester.