Question Library

Aquatic animals need oxygen to survive. Oil spills can have a severe impact on aquatic life, causing a drastic reduction in the number of aquatic animals. The oil spills tend to hinder dissolved oxygen transfer in the water.Even small amounts of hydrocarbons can prevent oxygen from transferring in the water column.The oil layer directly can also cause the dissolved oxygen level in the water to become low due to the obstruction of the diffusion process from the air. Nitrification in water bodies is caused by nitrifying bacteria converting ammonia and other nitrogen compounds into nitrite and nitrate. This process is affected by several environmental factors, including temperature, oxygen, pH, and light. Detoxification of water is the process of removing harmful components from wastewater. This process is necessary to treat water and wastewater that contain toxic compounds that can harm human health and the environment. Water disinfection occurs when physical or chemical processes disrupt the cell walls or membranes of microorganisms. This prevents the microorganisms from multiplying and causes them to die.

When water reacts with alkali metals such as sodium, alkali are formed. The reason they are called alkali metals. Also, the colour change from white anhydrous copper(II) tetraoxosulphate(VI) to blue hydrated copper(II) tetraoxosulphate(VI) is a way of testing for the presence of water. This colour change is a simple and effective way to detect the presence of water in a substance or environment.

A nuclear reaction that occurs when an atom is bombarded with a neutron is called a neutron bombardment reaction. When a nucleus is hit by a neutron, it can split into two or more smaller nuclei, releasing energy in a process called nuclear fission.Neutron has a mass number of 1 and no atomic number.

NH\(_4\)Cl, I\(_2\), S\(_8\) all undergo sublimation. i.e changes from solid to gaseous substances without first changing to liquid, when heated but CaCO\(_3\) does not.

Oxidation is a chemical reaction that occurs when the oxidation number of an atom increases. This means that the atom loses electrons and has a greater positive charge or a lesser negative charge. The oxidation number of an atom is a number that represents the degree of oxidation of the atom in a chemical compound.

An acid is considered strong if it dissociates completely into ions when mixed with water. When hydrochloric acid (HCl) dissolves in water, it dissociates into H\(^+\) and Cl\(^-\) . This is different from weak acids, like acetic acid, which only partially dissociate in water.

The naming starts with the first metal which is potassium, followed by the hexacyano (6 moles of Cyanide) and then ferrate (II).

Amphoteric oxides are metal oxides that can behave as both acidic and basic oxides. They react with acids and bases to produce water and salts. When dissolved in water, amphoteric oxides form alkaline solutions that contain hydroxide ions. E.g ZnO, Al\(_2\)O\(_3\),PbO etc The chemical reactions Al\(_2\)O\(_3\) + 6HCl → 2AlCl\(_3\) + 3H\(_2\)O and Al\(_2\)O\(_3\) + 2NaOH → 2NaAlO\(_2\) + H\(_2\)O show that Al\(_2\)O\(_3\) is amphoteric.

Cracking, saponification and polymerization are all terminologies associated with the petroleum industry but fermentation is associated with the brewery industry. Cracking is a chemical process that breaks down heavy hydrocarbon molecules into lighter, more useful ones. Saponification is a chemical reaction that converts fats and oils into soap. It's not directly involved in petroleum, but it can be used to analyze petroleum products. Polymerization is a process in the petroleum industry that converts light olefin gases into higher molecular weight hydrocarbons. Fermentation is the process in which a substance breaks down into a simpler substance. Microorganisms like yeast and bacteria usually play a role in the fermentation process, creating beer, wine, bread,yogurt and other foods.

Kerosene can thin synthetic and synthetic oil paints to make them spread more easily and shine more.

A reaction which is exothermic (\DeltaH negative) and results in an increase in the entropy of the system (\DeltaS positive) will always be spontaneous. Also, if \DeltaG is negative, the reaction will be spontaneous because the reaction can take place on it's own without any external source.

The indicator used in a titration between strong acid and weak base is methylorange while phenolphthalein is used in a titration between strong base and weak acid.

Nitrogen obtained from air is generally considered "impure" compared to chemically synthesized nitrogen because it contains trace amounts of atmospheric constituents that are difficult to separate entirely. Carbon (IV) oxide (CO₂) is the correct answer because it is typically removed early in the industrial process of separating nitrogen from air (such as passing air through caustic soda/sodium hydroxide). Therefore, the final nitrogen obtained is considered to no longer contain CO₂.

A solubility curve is a graph that plots the relationship between the solubility of a substance and temperature: Temperature: Plotted on the X-axis Solubility: Plotted on the Y-axis, measured in grams of solute per 100 grams of water

If 11.0g occupies 5.6 dm\(^3\) x will occupy 22.4 dm\(^3\) x = \(\frac{11\times 22.4}{5.6}\) x = 44g But Molecular mass = 2 x Vapour density 44 = 2 x Vapour density Vapour density = \(\frac{44}{2}\) = 22