1. Which one of the following is the softest?
Sodium is indeed the softest metal among the options listed. Sodium is a soft, silvery-white, highly reactive metal that can be easily cut with a knife. It's softer than lithium, aluminum, and iron.
2. Salts of which of the following elements provide colours to fireworks?
Strontium salts (like strontium carbonate) produce red colors in fireworks.
Barium salts (like barium nitrate) produce green colors in fireworks.
These elements are commonly used to create vibrant colors in pyrotechnics.
3. In which type of rocks are metals like Gold and Copper mostly found?
Metals like gold and copper are primarily found in old igneous rocks, which form from the cooling and solidification of molten magma. These metals often accumulate in veins or deposits within these rocks over geological time periods.
4. The vinegar is a solution of
Vinegar typically contains around 5% acetic acid by volume, with the remainder being water. It is used as a condiment, preservative, and in cooking for its tangy flavor.
5. In coloured galss. the purple colour is imparted by
Manganese oxide is commonly used to impart a purple color to glass. It works as a decolorizer in glass production, and depending on the quantity used, it can produce shades of purple or violet.
6. The quantum theory was first enunciated by
Max Planck is credited with formulating the quantum theory in 1900. He introduced the concept of "quanta" to explain blackbody radiation, which laid the foundation for quantum mechanics.
7. Which of the following is not a source of sulphur?
Carnalite is not a source of sulfur. It is a potassium magnesium chloride sulfate mineral, and while it contains sulfur in its sulfate component, it is not primarily considered a source of sulfur.
8. Which one of the following is also called stranger gas?
Xenon is a rare, colorless, odorless noble gas, often referred to as the "stranger gas" due to its unique characteristics. It has applications in medical imaging, such as in CT scans, and in space propulsion systems. Despite being chemically inert, xenon can form compounds with highly electronegative elements.
9. Which one of the following is also called stranger gas?
Xenon is often referred to as the "stranger gas" due to its unique properties as a noble gas and its rare ability to form compounds with other elements.
10. What is main component of gober gas?
Gober gas, also known as biogas, is primarily composed of methane (CH₄), which is produced through the anaerobic digestion of organic matter like animal dung (gober).
11. ____ is also known as marsh gas.
Methane is commonly known as marsh gas because it is produced in marshy or swampy areas through the decay of organic material in anaerobic conditions.
12. The element which shows least metallic character is
Boron is a metalloid and shows the least metallic character among the elements listed. It has properties intermediate between metals and non-metals.
13. The property of fluidity is absent in
Fluidity refers to the ability of a substance to flow. Solids have a fixed shape and do not flow, so they lack the property of fluidity.
14. Uranium eventually decays into a stable isotope of
Uranium decays through a series of radioactive transformations and eventually becomes a stable isotope of lead (Pb).
15. Nitrogen combines with metal to form
When nitrogen combines with a metal, it typically forms a compound called a nitride. Nitride compounds contain nitrogen in the form of the nitride ion (N³⁻) and are often found in metal alloys.
16. Wood is the main raw materials for the manufacture of
Wood is the main raw material used in the production of paper. It is processed into pulp, which is then turned into sheets of paper.
17. Which of the following is not a metallic mineral?
Gypsum is a non-metallic mineral. It is primarily used in the production of plaster, wallboard, and cement. The other minerals listed—Limonite, Bauxite, and Haematite—are metallic minerals.
18. The law of Octaves is due to
John Newlands, an English chemist, proposed the law of Octaves in 1864. He observed that when elements were arranged in order of increasing atomic mass, every eighth element had similar properties, resembling a musical octave. This led to the development of the periodic law, which later influenced the periodic table.
19. Glass is made from the mixture of
The primary ingredient for making glass is silica (sand), along with other substances like soda (sodium carbonate) and lime (calcium oxide). The mixture is heated to a high temperature to form glass.
20. Blue vitriol is
Copper sulfate (CuSO₄) is commonly known as blue vitriol due to its distinctive blue color. It is often used in agriculture as a fungicide and in chemistry for various reactions.
21. Tear gas is
Chlorine gas, when dispersed in a controlled form, can cause irritation to the eyes and respiratory system, leading to the "tear gas" effect. While other chemicals can be used in tear gas formulations, chlorine is one of the key agents in its production.
22. The gas originating in paddy field is
Methane is produced in paddy fields through the anaerobic decomposition of organic matter in waterlogged soil. The process is primarily carried out by methanogenic bacteria.
23. An element is best characterized by its
The atomic number uniquely identifies an element as it represents the number of protons in the nucleus of an atom of the element. It determines the element's position in the periodic table and its chemical properties.
24. Which of the following metal is the hardest one?
iron is harder than platinum, but platinum is still a durable and corrosion-resistant metal.
Platinum is a durable and corrosion-resistant metal, but it is not the hardest compared to other metals like iron. Iron, especially in its alloyed form as steel, is harder and more resistant to scratching. Lead and gold are softer metals, with platinum being tougher but not the hardest.
25. Teflon is a / an
Teflon, a trademarked brand name, is a type of fluoropolymer, which is a polymer that contains carbon-fluorine bonds. It is best known for its use as a non-stick coating on cookware.
26. Which one of the following mixtures is homogeneous?
Methanol and water form a homogeneous mixture because they completely mix at the molecular level, resulting in a single-phase solution. A homogeneous mixture has the same uniform appearance and composition throughout. The other options involve mixtures that do not blend uniformly.
27. The tendency of the elements to achieve noble gas configuration is called
The octet rule states that atoms tend to gain, lose, or share electrons to achieve a stable configuration with eight electrons in their outermost shell, similar to the noble gases.
28. Which one of the following is used in the synthesis of polythene?
Polythene (polyethylene) is synthesized through the polymerization of ethylene (C₂H₄), which is derived from ethane (C₂H₆). Ethane is cracked to produce ethylene, which is then polymerized to form polythene.
29. Which one of the following is not the component of nucleon?
A nucleon is a particle found in the nucleus of an atom and consists of:
Protons (positively charged particles)
Neutrons (neutral particles)
Electrons, on the other hand, orbit the nucleus and are not part of the nucleon. Similarly, positrons are the antiparticles of electrons and are also not components of nucleons.
30. The brown coal is
Lignite, also known as brown coal, is a type of coal that is younger and has a lower carbon content compared to other types of coal like bituminous or anthracite coal. It has a brownish color and is often used as a fuel source in power plants.
31. Which of the following is another name of RDX
RDX (Research Department Explosive), also known as Cyclonite, is a powerful explosive compound. It is commonly used in military and industrial applications.
32. Which of the following is not a metallic mineral?
Limonite, Hematite, and Bauxite are all metallic minerals (iron ore and aluminum ore, respectively).
Mica, on the other hand, is a non-metallic mineral commonly used in electrical and electronic applications, as it is an insulator.
33. Blue vitriol is:
Blue vitriol is the common name for copper sulfate (CuSO₄), which is a blue crystalline compound often used in agriculture, as a fungicide, and in chemical laboratories.
34. Tear gas is:
Cl₂ (chlorine gas) is toxic and corrosive, irritating the eyes, skin, and respiratory system. While it can be used as a chemical weapon, it is not classified as tear gas. Tear gases, like CS and CN, are specifically designed to cause temporary irritation and incapacitate individuals during crowd control.
35. Glass is made from the mixture of:
Glass is primarily made from a mixture of silica (sand), sodium carbonate, and calcium carbonate. The sand provides the silica, which forms the base structure of the glass, while calcium carbonate helps lower the melting point of the silica during the manufacturing process.
36. The law of Octaves is due to
The Law of Octaves was proposed by John Newlands in 1864. It states that when elements are arranged in increasing order of atomic weights, every eighth element exhibits similar properties, similar to the pattern of musical octaves.
37. Which one of the following is the softest?
Sodium is the softest among the listed metals. It is so soft that it can be easily cut with a knife. Magnesium, iron, and zinc are harder in comparison.
38. Salts of which of the following elements provide colours to fireworks?
Strontium produces a red color in fireworks, while Barium creates a green color. These elements are commonly used to produce vibrant colors in firework displays.
39. In which type of rocks are metals like Gold and Copper mostly found?
Metals like gold and copper are mostly found in old igneous rocks, which have undergone long geological processes. These metals are often concentrated in veins or pockets formed by the cooling and solidification of magma.
40. In coloured glass, the purple colour is imparted by:
Manganese oxide is used to impart a purple color to glass. It acts as a decolorizer when used in small quantities, and in higher concentrations, it creates a purple hue.
41. Vinegar is a solution of:
Vinegar typically contains about 5% acetic acid dissolved in water, which gives it its characteristic sour taste and makes it useful in cooking and as a preservative.
42. Galvanized iron sheets have a coating of
Galvanized iron sheets are coated with a layer of zinc to prevent rusting and corrosion. The process of galvanization involves coating iron or steel with zinc, which acts as a protective barrier.
43. Balloons are filled with
Balloons are typically filled with helium because it is lighter than air and non-flammable, making it safer than hydrogen, which was historically used but is highly flammable. Helium allows the balloon to float.
44. The most convenient was of expressing concentration is
Molarity (M) is the most convenient way of expressing the concentration of a solution. It is defined as the number of moles of solute per liter of solution, and it is widely used in laboratory settings for preparing solutions and performing calculations.
45. Energy produced in nuclear reaction is given by
The energy produced in a nuclear reaction is given by Einstein's law, specifically his famous equation E = mc².
This equation shows that energy (E) is equal to mass (m) multiplied by the square of the speed of light (c), which explains how mass can be converted into a large amount of energy in nuclear reactions.
46. Which one of the following has maximum calorific value
The calorific value is a key factor in determining the efficiency of a fuel, and the higher the calorific value, the more energy can be obtained from the fuel per unit of weight or volume. As mentioned, coal gas has the highest calorific value compared to producer gas, water gas, and oil gas, which makes it the most efficient fuel among these options
47. Which one of the following is also called stranger gas?
Xenon is often referred to as the "stranger gas" due to its rare and inert nature in the atmosphere.
48. _____ is also known as marsh gas.
Methane is commonly known as marsh gas because it is produced in marshy or swampy areas during the decomposition of organic matter.
49. What is the main component of gober gas?
Gober gas, also known as biogas, is primarily composed of methane. It is produced from the anaerobic decomposition of organic matter, such as animal dung (gober).
50. Which of the following is not a source of sulfur?
Carnallite is not a source of sulfur. Instead, it is a valuable source of potassium and magnesium, particularly used in the production of fertilizers. It is composed of potassium magnesium chloride (KMgCl₃·6H₂O) and is primarily found in marine salt deposits and evaporite formations.
51. The quantum theory was first enunciated by
Max Planck first enunciated the quantum theory in 1900. He proposed that energy is emitted or absorbed in discrete quantities, called "quanta," which laid the foundation for quantum mechanics.
52. Galvanized iron sheets have a coating of:
Galvanized iron sheets are coated with zinc to protect them from corrosion. This process is known as galvanization, and the zinc layer acts as a protective barrier against rust.
53. Balloons are filled with:
Balloons are commonly filled with helium because it is lighter than air and non-flammable, making it safer than hydrogen, which is highly flammable.
54. The most convenient was of expressing concentration is
Molarity is the most commonly used method to express the concentration of a solution. It is defined as the number of moles of solute per liter of solution. Molarity is widely used in chemistry because of its simplicity and direct relationship to the volume of the solution.
55. Energy produced in nuclear reaction is given by
The energy produced in nuclear reactions is explained by Einstein's famous equation E = mc sq , where E is the energy, m is the mass, and c is the speed of light.