Correct Answer: A) ascorbic acid and citric acid

Explanation

Ascorbic acid, also known as vitamin C, is a naturally occurring organic compound found in many fruits and vegetables, including citrus fruits. It is an essential nutrient for humans and plays a crucial role in various biological processes, such as collagen synthesis and the immune system's functioning.

Citric acid is another organic acid found in citrus fruits, such as lemons, oranges, and grapefruits. This weak acid contributes to the sour taste of these fruits and is also used as an additive in various food and beverage products to provide a sour or tart flavor.

Together, ascorbic acid and citric acid are responsible for the characteristic sour taste of citrus fruits, and they are the correct answer to this question.

Correct Answer: B) Hg²⁺

Correct Answer: C) gas is dispersed in liquid

Correct Answer: D) it is less expensive

Explanation

Detergent is a cleaning agent that is commonly used for washing clothes and dishes. It is more efficient than soap in cleansing because it has a unique chemical structure. One of the reasons why detergent is more efficient than soap is that it is not affected by the hardness of water, unlike soap. Hard water contains minerals such as calcium and magnesium that can react with soap to form insoluble compounds that stick to clothes and dishes, making them difficult to clean. Detergents, on the other hand, have a special structure that allows them to work well in both hard and soft water.

Another reason why detergent is more efficient than soap is that it cleans better than soap. Detergents contain surfactants, which are molecules that break down the surface tension between water and dirt, allowing them to be easily washed away. Soap, on the other hand, has a limited ability to dissolve in water, making it less effective in removing dirt and stains.

Additionally, the corresponding calcium and magnesium compounds formed when detergents react with hard water are soluble in water, which means they can be easily rinsed away. This is not the case with soap, as the compounds formed are insoluble and will remain on the clothes or dishes.

However, the given question asks us to identify the reason why detergent is not more efficient than soap, and the correct option is D, which states that detergent is less expensive than soap. This is not a reason why detergent is less efficient than soap, but rather a benefit for users who can save money by using detergent instead of soap.

Correct Answer: A)

H\(_2\)S, SO\(_2\) and oxides of nitrogen

Correct Answer: B) over a narrow range of temperature

Explanation

The correct answer is Option B: over a narrow range of temperature. A pure solid usually melts over a narrow range of temperature because it has a specific melting point. This means that the temperature at which it changes from solid to liquid is very precise and doesn't vary much.

In contrast, an impure solid may have a lower melting point and may melt over a wider range of temperature than a pure solid. This is because impurities can disrupt the crystal structure of the solid and make it more difficult for the solid to transition to a liquid state at a specific temperature.

Understanding the melting behavior of solids is important in many areas of Chemistry, including materials science, geochemistry, and environmental chemistry. Different substances have different melting points, and this can affect how they are used or processed in different industries.

To learn more about this, please read the relevant sections of the recommended textbooks.

Correct Answer: C)

SO\(_2\), CO and NO\(_2\)

Correct Answer: C) hydrogen bonding

Correct Answer: D) The rate of the forward reaction is equal to the rate of the reverse reaction

Explanation

Option D: The rate of the forward reaction is equal to the rate of the reverse reaction.

It's important to understand that at equilibrium, the reaction doesn't stop, but the forward and reverse reactions continue to occur at the same rate. This means that the amount of reactants and products in the system remains constant over time, but not necessarily equal to each other.

Also, note that the equilibrium constant, K, is a value that can help describe the position of the equilibrium. It is the ratio of the concentrations of the products to the concentrations of the reactants, each raised to the power of their respective stoichiometric coefficients. The value of K gives an indication of how much products or reactants are favored at equilibrium. If K > 1, the products are favored, and if K< 1, the reactants are favored.

Correct Answer: D) ethanoic acid