A quick 25 questions article on Chemistry – General Knowledge – MCQs – Chemistry Objective GK Mock Test – 1 like on nitrogen oxidation number, octance number, temporary hardness of water, nuclear fuel etc.
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Table of Contents
Que (1): Which type of glass is used for making glass reinforced plastic?
A. Tempered glass
B. Quartz glass
C. Swytch glass
D. Retrofitting glass.
Answer: Quartz Glass
Explanation: Also known as fibreglass is a composite material using quartz glass. In terms of properties it is strong, light and highly versatile.
Que (2): Which element that does not occur in nature but can be produced artificially?
Explanation: With an atomic number of 94 it is very radioactive element which forms a dull coating over it when oxdized.
Que (3): Which is the element that has the highest first ionization potential?
Explanation: Nitrogen is a colorless odorless gas at normal temperature. It is normally attached to another nitrogen atom, making a nitrogen molecule (N2). This bond is very strong. That is why many explosives contain nitrogen. The bond is broken when the explosive is made.
Que (4): By which number the quality of gasoline’ sample is determined?
A. Octance Number
B. Heptance number
C. Propance Number
Answer: Octance Number
Explanation: It basically reflects the resistance for engine knock, higher the octane number the more compression is required for fuel ignition. Low octane number leads to pre-ignition and subsequently damage to engine.
Que (5): Which transition metal is in liquid state?
Explanation: Set of elements occupying the central block of the periodic table.
Que (6): Which metal is non toxic in nature?
Explanation: Gold is a chemical element with the symbol Au and atomic number 79, making it one of the higher atomic number elements that occur naturally. In its purest form, it is a bright, slightly reddish yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal and a group 11
Que (7): ‘Gobar gas’ contains mainly which gas?
Explanation: Biogas is the mixture of gases produced by the breakdown of organic matter in the absence of oxygen, primarily consisting of methane and carbon dioxide. Biogas can be produced from raw materials such as agricultural waste, manure, municipal waste, plant material, sewage, green waste or food waste.
Que (8): Which rocks is transformed into marble?
D. Basalt rock
Explanation: Some marble also forms by contact metamorphism when a hot magma body heats adjacent limestone or dolostone. Before metamorphism, the calcite in the limestone is often in the form of lithified fossil material and biological debris. During metamorphism, this calcite recrystallizes and the texture of the rock changes.
Que (9): How are Oxygen and ozone?
Explanation: Allotropy or allotropism is the property of some chemical elements to exist in two or more different forms, in the same physical state, known as allotropes of the elements.
Que (10): Temporary hardness of water is due to the presence of which thing?
A. Sodium bicarbonate
B. Magnesium Bicarbonate
C. Potassium Bicarbonate
D. Cesuim Bicarbonate
Answer: Magnesium bicarbonate
Explanation: Calcium and magnesium dissolved in water are the two most common minerals that make water “hard.” The degree of hardness becomes greater as the calcium and magnesium content increases and is related to the concentration of multivalent cations dissolved in the water.
Que (11): Which oxyacid of halogen has maximum acidic nature?
Explanation: Fluorine has a very small size and high electronegativity. Therefore, it forms only one oxoacid, HOF which is known as fluoric(I) acid or hypofluorous acid. The other elements of the halogen family form several oxoacids.
Que (12): Thermal decomposition of alkanes is known as which name?
Explanation: Cracking allows large hydrocarbon molecules to be broken down into smaller, more useful hydrocarbon molecules. Fractions containing large hydrocarbon molecules are heated to vaporise them. They are then: heated to 600-700°C.
Que (13): What is the characteristic odour of garlic?
A. A sulphur compound
B. a sulphate
C. a hydrolic compound
D. none of these
Answer: A sulphur compound Allium Sativum
Explanation: Garlic (Allium sativum) is a species in the onion genus, Allium. … Garlic is known to cause bad breath (halitosis) and body odor, described as a pungent “garlicky” smell to sweat. This is caused by allyl methyl sulfide (AMS).
Que (14): Which of the following is good nuclear fuel?
Explanation: Plutonium 239: an artificial fissile nucleus, highly sought-after and feared. Plutonium, the ninety-fourth element in Mendeleyev’s periodic table, is an artificial radioactive nucleus produced in large quantities by reactors when nuclei of uranium 238 capture an extra neutron apiece.
Que (15): Which is the essential element in all organic compounds?
Explanation: The ‘essential element’ in all ‘organic compounds’ is Carbon. Explanation: ‘Organic Chemistry’ is the ‘branch of Chemistry’ that deals with the studying of the organic compounds or compounds containing Carbon in them
Que (16): Salts of which element pre vide colours to fireworks?
D. Strontium and Barium
Answer: Strontium and barium
Explanation: The colors in fireworks are created by the use of metal salts. Metal salts commonly used in firework displays include: strontium carbonate (red fireworks), calcium chloride (orange fireworks), sodium nitrate (yellow fireworks), barium chloride (green fireworks) and copper chloride (blue fireworks)
Que (17): Which type of coal is difficult to light in the open air?
Explanation: Lignite) have to be heated with an external heat source to a point where combustion starts.
Que (18): What does Oxidation involve?
A. Lossof electrons
B. Gain of electrons
C. Merging of atoms
D. Merging of atoms only with oxygen
Answer: Loss of electrons
Explanation: It happens when an atom or compound loses one or more electrons. Some elements lose electrons more easily than others. These elements are said to be easily oxidized.
Que (19): In colourful diamond, Why are different colours present?
A. Because of the cutting
B. Because of reflection
C. Because of refraction
D. Due to impuritites
Answer: Due to impurities
Explanation: Diamonds occur in a variety of colors—steel gray, white, blue, yellow, orange, red, green, pink to purple, brown, and black. Colored diamonds contain interstitial impurities or structural defects that cause the coloration; pure diamonds are perfectly transparent and colorless.
Que (20): What is the number of unpaired electrons in carbon atom?
Explanation: By Hund’s rule, the electron configuration of carbon, which is 1s 2 2s 2 2p 2, is understood to correspond to the orbital
Que (21): In an atom the order of filling up of the orbitals is governed by which principle?
A. Dalton’s principle
B. Pauli Exclusion Principle
C. Heisenberg principle
D. Aufbau principle
Answer: Aufbau principle
Explanation: This diagram is also referred as Aufbau principle diagram and is used to remember the order of the filling of the orbitals. According to Aufbau rule: First electrons are filled in 1s orbital. Since each orbital can accommodate a maximum of only 2 electrons so 1s orbital contains 2 electrons.
Que (22): Heating pyrites in air to remove sulphur is known as which name?
Explanation: Roasting is a process in metallurgy in which a sulfide ore is heated in air. The process may convert a metal sulfide to a metal oxide or to a free metal.
Que (23): What is reduction of oxide with carbon at high temperature called?
Explanation: Reduction of the oxide with carbon at high temperature is known as smelting. … are reduced by strongly heating them with coal or coke, in the blast furnace.
Que (24): Purification of petroleum is carried out by which method?
D. Fractional distillation
Answer: Fractional distillation
Explanation: Fractional distillation is the process by which oil refineries separate crude oil into different, more useful hydrocarbon products based on their relative molecular weights in a distillation tower.
Que (25): Which petroleum refinery product has the lowest boiling point?
D. all of them
Explanation: This property makes kerosene a relatively safe fuel to store and handle. With a boiling point between about 150 and 300 °C.
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