Chemistry Quiz

Which of the following substances is an example of a fine chemical?

• Sodium hydroxide

• Hydrochloric acid

• Ethylene

• Ammonia

Answer explanation

Ethylene is classified as a fine chemical due to its specific applications in the production of plastics and other specialty chemicals, while sodium hydroxide, hydrochloric acid, and ammonia are bulk chemicals.

The IUPAC name of the compound represented by the structure below is ?

• 2- chloro but-I ,3-diene.

• But-1,3-chlorodiene.

• 2-chloro but-diene.

• 3 -chloro but -1.3-diene.

Answer explanation

The correct IUPAC name is But-1,3-chlorodiene, as it indicates the presence of a chlorine substituent at position 3 and double bonds at positions 1 and 3, following the proper naming conventions.

Which of the following substances is a polypeptide?

• Starch

• Glycogen

• Protein

• Fats

Answer explanation

A polypeptide is a chain of amino acids, which makes up proteins. Starch and glycogen are polysaccharides, while fats are lipids. Therefore, the correct answer is protein, as it is the only polypeptide among the options.

Which of the following products could be formed during incomplete combustion of a hydrocarbon?

• I only

• I and II only

• I and III only

• II and III only

Answer explanation

Incomplete combustion of hydrocarbons typically produces carbon monoxide (I) and soot (III), while complete combustion yields carbon dioxide. Therefore, the correct answer is I and III only.

What quantity of electrons is lost when one mole of iron (II) ions is oxidized to iron (III)?

• 0 mole

• 3 moles

• 1 mole

• 2 moles

Answer explanation

When iron (II) ions (Fe^2+) are oxidized to iron (III) ions (Fe^3+), they lose 1 electron per ion. Therefore, for 1 mole of Fe^2+, 2 moles of electrons are lost to convert to Fe^3+, making the correct answer 2 moles.

What is the mass of silver deposited when 24,125 C of electricity is passed through a solution of silver salt. [Ag = 108, IF = 96,500 C ]

• 432g

• 108g

• 54g

• 27g

Answer explanation

Using the formula m = (Q * M) / (n * F), where Q = 24125 C, M = 108 g/mol, n = 1 (for Ag), and F = 96500 C/mol, we find m = (24125 * 108) / 96500 = 432 g. Thus, the mass of silver deposited is 432g.

Equal masses of calcium trioxocarbonate(iv) were added to dilute hydrochloric acid at the temperature specified. Under which of the following conditions would the reaction be slowest?

• Calcium trioxocarbonate ( iv ) chips at 20°C

• Calcium trioxocarbonate (IV) chips at 40°C

• Calcium trioxocarbonate (IV) powder at 20°C

• Calcium trioxocarbonate (IV) powder at 40°C

Answer explanation

The reaction is slowest with calcium trioxocarbonate (IV) powder at 40°C because, despite higher temperature generally increasing reaction rates, the fine powder increases surface area, leading to faster reactions. Thus, the combination is counterintuitive.

The high solubility of ethanol in water is due to?

• its low boiling point.

• its low freezing point.

• its covalent nature

• hydrogen bonding

Answer explanation

The high solubility of ethanol in water is primarily due to hydrogen bonding. Ethanol can form hydrogen bonds with water molecules, allowing it to mix well, unlike the other options which do not directly influence solubility.

Which of the following pairs of properties of alkali metals decreases down the group?

• First ionization energy and reactivity

• melting point and atomic radius

• Reactivity and electronegativity

• First ionization energy and melting point

Answer explanation

As you move down the group of alkali metals, the first ionization energy decreases due to increased atomic size and shielding effect. Reactivity increases as it becomes easier to lose the outer electron, making 'First ionization energy and reactivity' the correct choice.

The most suitable process of obtaining water from an aqueous solution of sugar is?

• Crystallization

• Distillation

• Filtration

• Decantation

Answer explanation

Distillation is the most suitable process for obtaining water from a sugar solution, as it separates components based on their boiling points, allowing water to evaporate and be collected, leaving sugar behind.