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Chemistry test

Description: This test is based on certain topics from all the branches of chemistry.
Number of Questions: 25
Created by:
Tags: Acids Bases & Salts metallurgy ligands etc Hydrolysis of Salts Proteins Some Important Polymers Acid-Base Titrations Electrode Potential, Standard Electrode Potential
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The salt used in gold mining and electroplating is

  1. calcium carbonate

  2. sodium carbonate

  3. sodium acetate

  4. potassium cyanide


Correct Option: D
Explanation:

Potassium cyanide is an inorganic compound with the formula KCN. This colorless crystalline compound, similar in appearance to sugar, is highly soluble in water. Most KCN is used in gold mining, organic synthesis, and electroplating. Smaller applications include jewellery for chemical gilding and buffing.

The salt used in some eco-friendly cleaning products is

  1. sodium silicate

  2. sodium sulphide

  3. sodium percarbonate

  4. potassium metabisulphite


Correct Option: C
Explanation:

Sodium percarbonate is a chemical, an adduct of sodium carbonate and hydrogen peroxide (a perhydrate), with formula Na2CO3·1.5H2O2. It is a colorless, crystalline, hygroscopic and water-soluble solid. It is used in some eco-friendly cleaning products and as a laboratory source of anhydrous hydrogen peroxide.

Melanin provides the skin and hair its natural colour. Which of the following salts is used to bleach melanin ?

  1. Copper sulphate

  2. Potassium permanganate

  3. Nickel chloride

  4. Magnesium sulphate


Correct Option: B
Explanation:

Potassium permanganate is an inorganic chemical compound with the formula KMnO4. It is a salt consisting of K+ and MnO4 ions. It is a strong oxidizing agent. Potassium permanganate is one of the principal chemicals used in the film and television industries to age props and set dressings.  In histology, it is used to bleach melanin which obscures tissue detail.

The protein regulating the modulation of cell adhesion and migration is

  1. aggrecan

  2. versican

  3. brevican

  4. neurocan


Correct Option: D
Explanation:

Neurocan core protein is a protein that in humans is encoded by the NCAN gene. Neurocan is a chondroitin sulphate proteoglycan consisting of neurocan and chondroitin sulphate. It is thought to be involved in the modulation of cell adhesion and migration.

Among the following salts which one is historically called bay salt?

  1. Acid salt

  2. Alkali salts

  3. Rock salt

  4. Sea salt


Correct Option: D
Explanation:

Sea salt , obtained by the evaporation of seawater, is used in cooking and cosmetics. It is historically called bay salt or solar salt. Generally more expensive than table salt, it is commonly used in gourmet cooking and specially potato chips.

Which among the following proteins is highly toxin in nature?

  1. Collectin

  2. Abrin

  3. Ricin

  4. Legume lectin


Correct Option: C
Explanation:

Ricin, from the castor oil plant Ricinus communis, is a highly toxic, naturally occurring protein. A dose as small as a few grains of salt can kill an adult.

Cyanotype is a photographic printing process .The salt used in this process is

  1. sodium chromate

  2. potassium dichromate

  3. potassium ferricyanide

  4. cobalt(II) chloride


Correct Option: C
Explanation:

Potassium ferricyanide is the chemical compound with the formula K3[Fe(CN)6]. This bright red salt contains the octahedrally coordinated [Fe(CN)6]3− ion. The compound has widespread use in blueprint drawing and in photography (Cyanotype process). Potassium ferricyanide is used as an oxidizing agent to remove silver from negatives and positives, a process called dot etching.

Semi synthetic polymers are prepared by chemical synthesis from natural materials. Which among the following is a semi-synthetic polymer?

  1. Rayon

  2. Cellulose acetate

  3. Modacrylic

  4. Olefin


Correct Option: A
Explanation:

Rayon is a manufactured regenerated cellulose fiber. Because it is produced from naturally occurring polymers, it is neither a truly synthetic fiber nor a natural fiber; it is a semi-synthetic or artificial fiber. Rayon is known by the names viscose rayon and art silk in the textile industry. It usually has a high luster quality giving it a bright sheen.

Which of the following polymers has excellent colour fastness?

  1. Nylon

  2. Acrylic

  3. Polytetrafluoroethylene

  4. Technora


Correct Option: B
Explanation:

Acrylic fibers are synthetic fibers made from a polymer (polyacrylonitrile) with an average molecular weight of ~100,000, about 1900 monomer units. It s lightweight, soft, and warm, with a wool-like feel. Acrylic is coloured before it is turned into a fiber as it does not dye very well but has excellent colour fastness. 

Among the following which one is created by certain kinds of marine and freshwater bivalve molluscs?

  1. Alpaca fleece

  2. Angora fibre

  3. Mohair

  4. Byssus


Correct Option: D
Explanation:

Byssus means both a silky filament by which certain molluscs attach themselves to hard surfaces, and a rare fabric, also called sea silk and its fibre source. It generally refers to a filament created by certain kinds of marine and freshwater bivalve molluscs, which use it to attach themselves to rocks, substrates or sea beds.

The fibres made up of cellulose obtained from beech trees is

  1. vinyon

  2. spandex

  3. vinylon

  4. modal


Correct Option: D
Explanation:

Modal is a cellulose fiber made by spinning reconstituted cellulose from beech trees. It is about 50% more hygroscopic (water-absorbent) per unit volume than cotton. It takes dye like cotton, and is colour-fast when washed in warm water. Modal is essentially a variety of rayon. Textiles made from modal are resistant to shrinkage and fading, but prone to stretching and pilling.

The yarn or wool spun from dog hair is known as

  1. cashmere

  2. chiengora

  3. qiviut

  4. sinew


Correct Option: B
Explanation:

Chiengora is a yarn or wool spun from dog hair. It is up to 80% warmer than wool and is not elastic. Often chiengora is blended with wool during the carding process. This blend has some give to it, which is preferable when knitting. It is also often blended with wool in order to create a yarn with less heat insulation.

The protein associated with the consolidation of long-term memory is

  1. cadherins

  2. ependymin

  3. integrins

  4. selectins


Correct Option: B
Explanation:

Ependymin is a glycoprotein associated with the consolidation of long-term memory, claims involving protection from strokes and neuronal regeneration.

Macrophages are the body's first line of defense and have many roles.The protein present on the surface of macrophages is

  1. calnexin

  2. galectins

  3. calreticulin

  4. sialoadhesin


Correct Option: D
Explanation:

Sialoadhesin is a cell adhesion molecule found on the surface of certain cells of the immune system called macrophages. It is found in especially high amounts on macrophages of the spleen, liver, lymph node, bone marrow, colon, and lungs. Also, in patients suffering from rheumatoid arthritis, the protein has been found in great amounts on macrophages of the affected tissues.

The welding technique used for joining material over 6 mm thick is

  1. hot gas welding

  2. freehand welding

  3. extrusion welding

  4. speed welding


Correct Option: C
Explanation:

Extrusion welding allows the application of bigger welds in a single weld pass. It is the preferred technique for joining material over 6 mm thick. Welding rod is drawn into a miniature hand held plastic extruder, plasticized, and forced out of the extruder against the parts being joined, which are softened with a jet of hot air to allow bonding to take place.

Colloids are heterogeneous systems.These are characterized by ----------------------- titration.

  1. redox

  2. acid base

  3. gas phase

  4. zeta potential


Correct Option: D
Explanation:

These titrations characterize heterogeneous systems, such as colloids. Zeta potential plays role of indicator. One of the purposes is the determination of iso-electric point when surface charge becomes 0. This can be achieved by changing pH or adding surfactant. Another purpose is determination of the optimum dose of the chemical for flocculation or stabilization.

There are three states of matter namely solid liquid & gas. Which of the following spectroscopies is independent of states of matter?

  1. Atomic absorption spectroscopy

  2. Spark or arc atomic emission spectroscopy

  3. Inductively coupled plasma atomic emission spectroscopy

  4. Laser-induced breakdown spectroscopy


Correct Option: D
Explanation:

aser-induced breakdown spectroscopy (LIBS) is a type of atomic emission spectroscopy which uses a highly energetic laser pulse as the excitation source. The laser is focused to form a plasma, which atomizes and excites samples. In principle, LIBS can analyse any matter regardless of its physical state, be it solid, liquid or gas.

The two plastic parts having a complex weld joint geometry are welded by

  1. contact welding

  2. ultrasonic welding

  3. injection welding

  4. hot plate welding


Correct Option: D
Explanation:

Related to contact welding, this technique is used to weld larger parts, or parts that have a complex weld joint geometry. The two parts to be welded are placed in the tooling attached to the two opposing platens of a press. A hot plate, with a shape that matches the weld joint geometry of the parts to be welded, is moved in position between the two parts. The two opposing platens move the parts into contact with the hot plate until the heat softens the interfaces to the melting point of the plastic.

A number of techniques are used for welding plastics (polymers). Lower frequency and higher amplitude are used in ------------------- welding.

  1. solvent

  2. laser

  3. spin

  4. friction


Correct Option: D
Explanation:

In friction welding, the two parts to be assembled are rubbed together at a lower frequency (typically 100-300 Hz) and higher amplitude than ultrasonic welding. The friction caused by the motion combined with the clamping pressure between the two parts creates the heat which begins to melt the contact areas between the two parts. At this point, the plasticized materials begin to form layers that intertwine with one another, which therefore results in a strong weld.

Among the following electrodes which one is a type of redox electrode?

  1. Palladium-hydrogen electrode

  2. Plate electrode

  3. Quinhydrone electrode

  4. Potassium selective electrodes


Correct Option: C
Explanation:

The quinhydrone electrode is a type of redox electrode which can be used to measure the hydrogen ion concentration (pH) of a solution in a chemical experiment. It provides an alternative to the commonly used glass electrode in a pH meter. The electrode consists of an inert metal electrode (usually a platinum wire) in contact with quinhydrone crystals and a water-based solution.

The carbon dioxide measuring electrode is

  1. the saturated calomel electrode

  2. the severinghaus electrode

  3. a silver chloride electrode

  4. the standard hydrogen electrode


Correct Option: B
Explanation:

The Severinghaus electrode is an electrode that measures carbon dioxide (CO2). It utilizes a CO2-sensitive glass electrode in a surrounding film of bicarbonate solution covered by a thin plastic carbon dioxide permeable membrane, but impermeable to water and electrolytic solutes. The carbon dioxide pressure of a sample gas or liquid equilibrates through the membrane and the glass electrode measures the resulting pH of the bicarbonate solution.

Which of the following ammonium salts is also known as baker's ammonia ?

  1. Ammonium carbonate

  2. Ammonium chloride

  3. Ammonium nitrate

  4. Ammonium hexachloroplatinate


Correct Option: A
Explanation:

Ammonium carbonate is a commercial salt with the chemical formula (NH4)2CO3. It is used when crushed as a smelling salt. It can be crushed when needed in order to revive someone who has fainted. It is also known as baker's ammonia and was a predecessor to the more modern leavening agents: baking soda and baking powder.

In an electrochemical cell, an electrode is of two types (anode & cathode). Which of the following electrodes is a conjunction of a solid, liquid and gaseous interface?

  1. Cellulose electrode

  2. Auxiliary electrode

  3. Clark electrode

  4. Gas diffusion electrodes


Correct Option: D
Explanation:

Gas diffusion electrodes (GDE) are electrodes with a conjunction of a solid, liquid and gaseous interface, and an electrical conducting catalyst supporting an electrochemical reaction between the liquid and the gaseous phase.

Hydrodynamic voltammetry is an electrochemical technique in which a faradaic current passing through the electrolysis solution is measured while an appropriate potential is applied to the polarizable or indicator electrode.The electrode used in this process is

  1. a reference electrode

  2. a reversible hydrogen electrode

  3. a rotating disk electrode

  4. a rotating ring-disk electrode


Correct Option: D
Explanation:

A rotating ring-disk electrode (RRDE) is double working electrode used in hydrodynamic voltammetry, very similar to a rotating disk electrode (RDE). The electrode actually rotates during experiments inducing a flux of analyte to the electrode. These working electrode are used in electrochemical studies when investigating reaction mechanisms related to redox chemistry among other chemical phenomenon.

Polarography is an electrochemical method of quantitative or qualitative analysis based on the relationship between an increasing current passing.The electrode used in polarography is

  1. dropping mercury electrode

  2. dynamic hydrogen electrode (DHE)

  3. fluoride selective electrode

  4. ion-selective electrode


Correct Option: A
Explanation:

The dropping mercury electrode (DME) is a working electrode made of mercury and used in polarography. Experiments run with mercury electrodes are referred to as forms of polarography even if the experiments are identical or very similar to a corresponding voltammetry experiment which use solid working electrodes.

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