Chemistry – GK Questions

Ans: C

Explanation:Carbon monoxide (CO) is a highly toxic gas produced by incomplete combustion. It binds to hemoglobin in the blood more readily than oxygen, preventing oxygen transport to the body’s tissues. This can lead to a range of symptoms, including headache, dizziness, nausea, visual disturbances, confusion, paralysis, and in severe cases, death. Carbon dioxide (CO2) is an asphyxiant but not directly toxic at typical atmospheric concentrations, and ozone (O3) is an irritant, particularly to the respiratory system, but the described symptoms are more characteristic of CO poisoning.
Correct_Option:C

Ans: A

Explanation:Nylon is a generic designation for a family of synthetic polymers known as polyamides. These polymers are characterized by the presence of amide groups in their molecular chain.
Correct_Option:A

Ans: B

Explanation:The Earth’s crust is primarily composed of silicate minerals. Oxygen is the most abundant element, making up about 46.6% of the crust by weight, followed by silicon at about 27.7%. These two elements combine to form silicate minerals, which are the building blocks of most rocks in the crust.
Correct_Option:B

Ans: B

Explanation:Residual chlorine is the amount of chlorine that remains in the water after disinfection. This remaining chlorine is important as it provides a continuing disinfection effect, preventing recontamination of the water. Free chlorine and free available chlorine are specific forms of residual chlorine, but residual chlorine is the general term encompassing all forms of chlorine remaining after disinfection. Combined available chlorine refers to chlorine that has reacted with ammonia or organic compounds, forming chloramines.
Correct_Option:B

Ans: B

Explanation:Stainless steel is primarily an alloy of iron, chromium, and carbon. Chromium is essential for its corrosion resistance, and carbon is added to improve its hardness and strength. Other elements may also be present in smaller quantities.
Correct_Option:B

Ans: A

Explanation:The head of a safety match typically contains red phosphorus, potassium chlorate, and sulfur. When the match is struck, friction ignites the mixture, producing heat and igniting the wood.
Correct_Option:A

Ans: C

Explanation:The ozone layer in the Earth’s stratosphere absorbs most of the Sun’s harmful ultraviolet (UV) radiation. Depletion of this ozone layer allows more UV radiation to reach the Earth’s surface.
Correct_Option:C

Ans: B

Explanation:Sodium vapour lamps work by passing an electric current through sodium vapor. This excites the sodium atoms, causing their electrons to jump to higher energy levels. When these electrons fall back to their ground state, they release energy in the form of photons. Sodium atoms preferentially emit photons in the yellow part of the visible spectrum, which is why the lamps glow yellow. Option B accurately describes this process of energy emission in the yellow region.

Correct_Option:B

Ans: B

Explanation:A buffer solution resists changes in pH when small amounts of acid or base are added, or when it is diluted. Dilution increases the concentration of both the weak acid and its conjugate base in the buffer system, but it does so proportionally. According to the Henderson-Hasselbalch equation (pH = pKa + log([conjugate base]/[weak acid])), if the ratio of the conjugate base to the weak acid remains constant (as it does upon dilution), the pH will not change.
Correct_Option:B

Ans: A

Explanation:Ozone is an allotrope of oxygen, meaning it is a different form of the same element. Its chemical formula is O3, indicating that each molecule of ozone consists of three oxygen atoms.
Correct_Option:A

Ans: A

Explanation:Water gas, also known as synthesis gas or syngas, is a fuel gas mixture consisting primarily of carbon monoxide (CO) and hydrogen (H2). It is typically produced by passing steam over heated coal or hydrocarbons.
Correct_Option:A

Ans: A

Explanation:Nylon is a synthetic polymer that belongs to the class of polymers known as polyamides. Its chemical structure consists of repeating amide linkages.
Correct_Option:A

Ans: D

Explanation:Titanium is a biocompatible metal that is highly resistant to corrosion in the human body. Copper, iron, and aluminum are more prone to corrosion and can release harmful ions into the body. Therefore, titanium is the preferred material for surgical implants like bone pins.
Correct_Option:D

Ans: C

Explanation:The Bureau of Indian Standards (BIS) for drinking water specifies the maximum permissible limit for total hardness as 500 mg/L (as CaCO3). However, a desirable limit is generally considered to be below 200 mg/L for palatability and to avoid scaling issues in pipes and appliances. For a banking exam’s current affairs section, the focus might be on the generally accepted acceptable limit or the upper permissible limit. Given the options, 200 mg/L is often cited as a desirable upper limit, while 500 mg/L is the absolute maximum. Without further context or clarification on whether the question asks for “desirable” or “permissible maximum”, both 200 and 500 have relevance. However, in many contexts, the acceptable limit is discussed as being around 200 mg/L for good quality drinking water. If the question strictly asks for “maximum permissible concentration”, 500 mg/L would be the technically correct answer according to BIS. But, given the options and the typical knowledge expected in such exams, 200 is often presented as the upper acceptable range before significant issues arise. Let’s assume the question leans towards the practical acceptable limit.

Correct_Option:C

Ans: B

Explanation:Iron is primarily extracted from iron ore, with haematite being one of the most important and widely used iron ores. Cinnabar is a source of mercury, bauxite is the primary ore for aluminum, and dolomite is a source of magnesium and calcium, not iron.
Correct_Option:B

Ans: D

Explanation:Mica is a group of alumino-silicate minerals known for their excellent electrical insulating properties, thermal stability, and resistance to heat and chemicals. These characteristics make them ideal for use in electrical insulators and various other electrical components. Bauxite is an ore of aluminum, chromite is an ore of chromium, and manganese is a metal.
Correct_Option:D

Ans: C

Explanation:The Great Smog of London in 1952 was a severe air pollution event caused by a combination of industrial emissions and coal burning, which mixed with fog to create a thick, toxic smog that resulted in thousands of deaths.
Correct_Option:C

Ans: D

Explanation:Calcium Sulphate (Gypsum) is commonly used as a fertilizer to provide calcium and sulfur, which are essential nutrients for plant growth. Calcium Carbonate can also be used to improve soil pH, but Calcium Sulphate is more directly a calcium source for plants. Calcium Carbide and Calcium Cyanide are not typically used as fertilizers.
Correct_Option:D

Ans: C

Explanation:Vinegar is a diluted solution of acetic acid. Acetic acid is the main component that gives vinegar its characteristic sour taste and pungent smell.
Correct_Option:C

Ans: C

Explanation:The ozone layer, which absorbs most of the Sun’s ultraviolet radiation, is primarily located in the lower portion of the Earth’s stratosphere, from approximately 15 to 35 kilometers (9 to 22 miles) above Earth.
Correct_Option:C