Chemistry GK Questions Quiz-33

Chemistry GK Questions Quiz-33

Chemistry Multiple Choice Questions (MCQs) Quiz for State and UPSC Civil Services Examinations. Objective Questions on Chemistry for competitive examinations.

    641. The gas causing acid rain in an industrial area is

    (1) Carbon dioxide
    (2) Carbon monoxide
    (3) Sulphur dioxide
    (4) Methane
    Answer:
    641. (3) The main gases responsible for causing acid rain are sulphur dioxide as well as nitrous oxides. The main sources of sulphur dioxide are metal working industries and coal-fired power stations whereas nitrous oxide is from vehicles and fuel combustion.

    642. The pH of lemon juice is expected to be

    (1) equal to 7
    (2) nothing can be predicted
    (3) less than 7
    (4) more than 7
    Answer:
    642. (3) The pH level of lemon juice is, 2.00 to 2.60. It varies depending on the lemon. pH expresses different levels of acidity or alkalinity within a solution.

    643. An example of heterocyclic compound is

    (1) Naphthalene 
    (2) Furan
    (3) Benzene 
    (4) Anthracene
    Answer:
    643. (2) A heterocyclic compound is a cyclic compound that has atoms of at least two different elements as members of its ring (s). Furan is a heterocyclic organic compound, consisting of a five-membered aromatic ring with four carbon atoms and one oxygen.

    644. In electro-refining, the pure metal is deposited on

    (1) vessel 
    (2) electrolyte
    (3) cathode 
    (4) anode
    Answer:
    644. (3) In electro-refining, the anodes consist of unrefined impure metal, and as the current passes through the acidic electrolyte the anodes are corroded into the solution so that the electroplating process deposits refined pure metal onto the cathodes. Electrolytic refining is used to extract impurities from crude metals.

    645. Natural rubber is a polymer of

    (1) Vinyl acetate 
    (2) Propene
    (3) Isoprene 
    (4) Styrene
    Answer:
    645. (3) Natural rubber consists of suitable polymers of the organic compound isoprene, with minor impurities of other organic compounds plus water. Isoprene is produced and emitted by many species of trees into the atmosphere (major producers are oaks, poplars, eucalyptus, and some legumes).

    646. Which is not an anasthetic agent in surgical operations?

    (1) Chloroform
    (2) Ether
    (3) Nitrous oxide
    (4) Acetone
    Answer:
    646. (4) The currently used inhalational anaesthetic agents are mainly: nitrous oxide, isoflurane, sevoflurane and desflurane. Chloroform, ether, ethylene are other anaesthetic agents. However, they are not widely used in clinical practice today.

    647. Brass is an alloy of :

    (1) Cu, Al and Zn
    (2) Cu and Sn
    (3) Cu and Zn
    (4) Al and Mg
    Answer:
    647. (3) Brass is an alloy made of copper and zinc. The proportions of zinc and copper can be varied to create a range of brasses with varying properties. By comparison, bronze is principally an alloy of copper and tin.

    648. Rectified spirit is :

    (1) 95% ethyl alcohol
    (2) 100% ethyl alcohol
    (3) methylated spirit iodine
    (4) tincture
    Answer:
    648. (1) Rectified spirit, also known as ethyl alcohol of agricultural origin, is highly concentrated ethanol which has been purified by means of repeated distillation, called rectification. It typically contains 95% alcohol by volume.

    649. Nylon is made up of :

    (1) Polyamide
    (2) Polyester
    (3) Polyethylene
    (4) Polypropylene
    Answer:
    649. (1) Nylon is a generic designation for a family of synthetic polymers known generically as aliphatic polyamides. It is one of the most commonly used polymers.

    650. Sweat contains water and _______.

    (1) Citric acid 
    (2) Lactic acid
    (3) Salt 
    (4) Vinegar
    Answer:
    650. (3) Sweat contains mainly water. It also contains minerals, lactate, and urea. It also contains a smaller amount of sodium chloride (main component of ordinary table salt).

    651. How many bones are there in a newly born infant ?

    (1) 206 
    (2) 230
    (3) 280 
    (4) 300
    Answer:
    651. (3) At birth, there are over 270 bones in an infant body. But many of these fuse together as the child grows, leaving a total of 206 separate bones in a typical adult.

    652. Radiations which is not emitted during radioactivity is :

    (1) a rays 
    (2) b ravs
    (3) g ravs 
    (4) Cathode rays
    Answer:
    652. (4) Radioactivity is the process by which a nucleus of an unstable atom loses energy by emitting particles of ionizing radiation. It includes the emission of energetic alpha particles (a), beta particles (b), and gamma rays (g).

    653. Citric acid is present in free form in

    (1) Tamarind 
    (2) Milk
    (3) Apple 
    (4) Lemon
    Answer:
    653. (4) Lemons, oranges, limes, and other citrus fruits naturally possess high concentrations of citric acid. The juice of the lemon is about 5% to 6% citric acid, which gives lemons a sour taste. In fact, Citric acid was first isolated in 1784 by the chemist Carl Wilhelm Scheele, who crystallized it from lemon juice.

    654. KMnO4 can be used as

    (1) Insecticide 
    (2) Fertilizer
    (3) Pesticide 
    (4) Disinfectant
    Answer:
    654. (4) Potassium permanganate is an inorganic chemical compound with the formula KMnO4. As an oxidant, potassium permanganate can act as an antiseptic. For example, dilute solutions are used to treat canker sores (ulcers), disinfectant for the hands and treatment for mild pompholyx, dermatitis, and fungal infections of the hands or feet. Potassium permanganate is used extensively in the water treatment industry.

    655. A thick paste of cement, sand and water is called

    (1) Concrete 
    (2) R.C.C.
    (3) Mortar 
    (4) Kiln
    Answer:
    655. (3) Mortar is a workable paste used to bind construction blocks together and fill the gaps between them. Modern mortars are typically made from a mixture of sand, a binder such as cement or lime, and water.

    656. Which of the following is not a chemical reaction'?

    (1) Burning of paper
    (2) Digestion ot" food
    (3) Conversion of water into steam
    (4) Burning of coal
    Answer:
    656. (3) The conversion of water into steam is an example of a physical change, where the state of the matter changes without changing its composition. A physical change involves a change in physical properties. Examples of physical properties include melting, transition to a gas, change of strength, change of durability, changes to crystal form, textural change, shape, size, color, volume and density.

    657. Which of the following is used as anesthetic ?

    (1) NH3 
    (2) NO
    (3) NO2 
    (4) N2O
    Answer:
    657. (2) Nitrous oxide (NO), commonly known as laughing gas or happy gas, is the most commonly used inhalation anesthetic in dentistry and is commonly used in emergency centers and ambulatory surgery centers as well. It is an inorganic inhalation agent that is colorless, odorless to sweet-smelling, and nonirritating to the tissues.

    658. The quality of petrol is expressed in terms of

    (1) Cetane number
    (2) Gold number
    (3) Octane number
    (4) Added unlead compounds
    Answer:
    658. (3) Octane rating or octane number is a standard measure of the of the ignition quality of gas (gasoline or petrol). Higher this number, the less susceptible is the gas to ‘knocking’ (explosion caused by its premature burning in the combustion chamber) when burnt in a standard (spark-ignition internal combustion) engine.

    659. The percentage of nitrogen in Air is

    (1) 0.94 
    (2) 0.03
    (3) 78.03 
    (4) 85.02
    Answer:
    659. (3) By volume, dry air contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases. Air also contains a variable amount of water vapor, on average around 1%.

    660. Antacids are found in drugs that give relief to

    (1) Eye sight
    (2) Stomach ache
    (3) Acne
    (4) Headache
    Answer:
    660. (2) An antacid is a substance which neutralizes stomach acidity. Antacids are taken by mouth to relieve heartburn, the major symptom of gastro-esophageal reflux disease, or acid indigestion which are a few of the common terms used to describe digestive upset.


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