Description : Thermosetting materials (A) Are cross-linked molecules (B) Soften on application of heat (C) Are solvent soluble (D) None of these
Last Answer : (A) Are cross-linked molecules
Description : Thermoplastic materials (A) Do not soften on application of heat (B) Are heavily branched molecules (C) Are solvent insoluble (D) None of these
Last Answer : (D) None of these
Description : Polymers which soften on heating and harden when cooled are (a) Cross-linked polymers (b) Copolymers (c) Thermosetting polymers (d) Thermoplastics
Last Answer : Thermoplastics
Description : The thermosetting plastic (A) Becomes rigid when moulded at suitable pressure and temperature (B) At 127°C to 177°C permanently set and further application of heat does not soften it (C) Chars at 343°C (D) All the above
Last Answer : Answer: Option D
Description : Cross linked polymers are (A) Thermoplastic (B) Thermosetting (C) Either (A) or (B) (D) Fibres only
Last Answer : (B) Thermosetting
Description : Pick out the wrong statement. (A) Linear polymers are formed from bifunctional groups only and are normally thermoplastic (B) Cross-linked branched chain polymers are either elastometric or ... (D) Dibasic acids reacts with dihydric alcohols to give polyesters using addition polymerisation reaction
Last Answer : D) Dibasic acids reacts with dihydric alcohols to give polyesters using addition polymerisation reaction
Description : Cross linked polymers formed from bi-and trifunctional groups in which cross-linkage in three dimensions via few chemical bonding across linear chains occur imparts to the polymer __________ properties. (A) Thermoplastic (B) Thermosetting (C) Elastometric (D) Brittleness
Last Answer : (C) Elastometric
Description : Pick out the wrong statement regarding the solubility characteristics of high polymers. (A) Greater the degree of cross-linking in the polymer, lesser is its solubility (B) Polymers having more ... of the solvent (D) High molecular weight polymers on dissolving gives solution of very low viscosity
Last Answer : (D) High molecular weight polymers on dissolving gives solution of very low viscosity
Description : Thermosetting resins/polymers as compared to thermoplastic ones are (A) Soluble in all organic solvents (B) More brittle (C) Formed by addition polymerisation only (D) Easily reshaped & reused
Last Answer : (B) More brittle
Description : Thermosetting resins are those polymers, which (A) Do not increase in plasticity with rise in temperature (B) Allow slip to occur between molecules (C) Do not take on a permanent set (D) None of these
Last Answer : (A) Do not increase in plasticity with rise in temperature
Description : Thermosetting plastic materials (A) Can be repeatedly melted (B) Is useful for melt casting (C) Cannot be melted after forming (D) Is useful for spinning
Last Answer : (C) Cannot be melted after forming
Description : All thermoplastic, thermosetting & elastic materials can be processed in a extrusion machine, however it cannot be used for the production of plastic (A) Filaments (B) Pipes (C) Buckets (D) Tubings
Last Answer : (C) Buckets
Description : Pick out the wrong statement. (A) Cellulose acetate membranes are used in dialysis process (B) Elutriation process refers to when the soluble material is largely concentrated on the surface of an ... that various streamflow from one to another (D) Zirconia probe is used for the humidity measurement
Last Answer : (D) Zirconia probe is used for the humidity measurement
Description : In a liquid-liquid extraction, 10 kg of a solution containing 2 kg of solute C and 8 kg of solvent A is brought into contact with 10 kg of solvent B. Solvent A and B are completely immiscible in each other whereas ... (C) Less than 1 kg of C is transferred to B (D) No amount of C is transferred to B
Last Answer : (A) The entire amount of C is transferred to solvent B
Description : The operation involved when the soluble material is largely on the surface of an insoluble solid and is merely washed off by the solvent is called (A) Decoction (B) Percolation (C) Elutriation or elution (D) None of these
Last Answer : (C) Elutriation or elution
Description : What is the purpose of plasticizers? (a) Harden plastics (b) Soften plastics (c) Initiate polymerizations (d) Cross-link polymer chains
Last Answer : Soften plastics
Description : Pick out the wrong statement. (A) 'Solvates' are chemical compounds formed by solute with their solvents. When water is the solvent, then it is called a 'hydrate' (B) In heat exchanger ... vertical evaporators, area of central downtake is about 50 to 100% of the total tube cross-sectional area
Last Answer : (C) Heat transfer co-efficient during nucleate boiling is not influenced by the agitation imparted
Description : Coenzymes are (A) Heat stable, dialyzable, non protein organic molecules (B) Soluble, colloidal, protein molecules (C) Structural analogue of enzymes (D) Different forms of enzymes
Last Answer : Answer : A
Description : (a) Show on a diagram the transfer of electrons between the atoms in the formation of MgO. Write symbols of cation and anion present in MgO. (b) Name the solvent in which ionic compounds are generally soluble. (c) Why are aqueous solutions of ionic compounds able to conduct electricity? -Chemistry
Last Answer : (b) Ionic compounds are soluble in water. (c) It is because aqueous solutions consist of ions which can move freely in them and carry current.
Description : What is solvent called soluble ?
Last Answer : The solvent that is dissolved is called solvent.
Description : When an organic compound is present in aqueous medium and is less soluble in any organic solvent, then it is separated by `:`
Last Answer : When an organic compound is present in aqueous medium and is less soluble in any organic ... B. distillation C. chromatography D. sublimation
Description : What would happen if is not soluble in the solvent?
Last Answer : Need answer
Description : Is RbOH soluble in non polar solvent?
Last Answer : It is not soluble in nonpolar solvents.
Description : Why is CuSO4 more soluble in water than in organic solvent?
Last Answer : CuSO4 is ionic and water is polar. The types of bonding allowwater to dissolve the salt much more easily than an organic solvent(e.g. alcohol, hexane) could.
Description : Why is CuSO4 more soluble in water than in an organic solvent and why is the reverse true salicylic acid?
Last Answer : Water and copper sulfate are both polar compound; polar compounds are dissolved better in polar solvents. Salycilic acid is also polar but the solubility is lower because the benzene ring has a negative effect.
Description : Lipids have the following properties: (A) Insoluble in water and soluble in fat solvent (B) High energy content (C) Structural component of cell membrane (D) All of these
Last Answer : Answer : D
Description : . In which solvent are alkenes most soluble? (a) water (b) ethyl alcohol (c) ammonia (d) carbon tetrachloride
Last Answer : carbon tetrachloride
Description : Polymers are classified into four categories namely thermosetting, thermoplastic, elastomer and fibre depending upon their (A) Molecular sizes (B) Magnitude of intermolecular forces (C) Resistance to heat (D) Polymerisation mechanism
Last Answer : (B) Magnitude of intermolecular forces
Description : Elastomers are (A) Thermosetting material (B) Exemplified by protein derivatives (C) Having high flexural strength (D) Having very high tensile strength and heat resistance
Last Answer : (C) Having high flexural strength
Description : Through which molecules of both solvent and liquid type can move easily ?
Last Answer : Molecules of both solvent and liquid type can move easily through cell wall.
Description : Which action best accounts for the solubility of aldehydes and ketones in water? (a) Polar interactions between solute molecules. (b) H-bonding between solute molecules. (c) Van der waals forces (d) H-bonding between solute and solvent molecules
Last Answer : H-bonding between solute and solvent molecules
Description : Why is moist heat more versatile than dry heat? a. It More Easily Penetrates Materials. b. Water Molecules Conduct Heat Better Than Air c. It Denatures Proteins By Changing Their Structure And Chemical Bonds d. A-C Are Correct
Last Answer : d. A-C Are Correct
Description : __________ polythene is most prone to stress-cracking (A) High density (B) Low density (C) Cross-linked (D) Linear low density
Last Answer : (A) High density
Description : In step growth polymerisation, generally only one type of reaction & some basic mechanism is involved. Step growth polymerisation reaction is not involved in the manufacture of (A) Cross linked polystyrene (B) Phenol formaldehyde resins (C) Polyesters (D) Polyamides
Last Answer : (A) Cross linked polystyrene
Description : . In a linear polymer, the monomeric units are linked together to form long straight chains. The cross linked or branched chain polymers compared to linear polymers have higher (A) Densities (B) Melting point (C) Tensile strength (D) Hardness, rigidity & brittleness
Last Answer : (D) Hardness, rigidity & brittleness
Description : Neoprene is rendered non-inflammable, because of (A) Its cross-linked structure (B) Its linear chain structure (C) The presence of chlorine atoms in its monomer (D) The absence of chlorine atoms in its monomer
Last Answer : (C) The presence of chlorine atoms in its monomer
Description : In a cross linked polymer, the monomeric units are linked together to constitute a three dimensional network. Which of the following is a crosslinked polymer? (A) Bakelite (phenol formaldehyde) (B) Polyester (C) Polythene (D) Nylon-6
Last Answer : (A) Bakelite (phenol formaldehyde)
Description : Covalent network crystals have-------? A. higher melting point then molecular crystals (Answer) B. lower melting point then molecular crystals C. discrete molecules linked by Van der waals forces D. hydrogen bonding
Last Answer : A. higher melting point then molecular crystals (Answer)
Description : Cellulose, the most important constituent of plant cell wall is made up of (a) branched chain of glucose molecules linked by β-1, 4 glycosidic bond in straight chain and α-1, 6 glycosidic bond ... the site of branching (d) unbranched chain of glucose molecules linked by α-1, 4 glycosidic bond.
Last Answer : (b) unbranched chain of glucose molecules linked by β-1, 4 glycosidic bond
Description : The purpose of nitriding the steel is to (A) Harden its surface (B) Soften its surface (C) Improve its reliability (D) None of these
Last Answer : (A) Harden its surface
Description : Do fats and water soluble molecules such as sugars get absorbed from the intestine directly into the blood?
Last Answer : The simple sugars do but not the fats. The presence of fat inthe small intestine produces hormones that stimulate the release ofpancreatic lipase from the pancreas and bile from the liver whichhelps in the emulsification of fats for absorption as fattyacids.
Description : Why cant Water soluble ions and molecules cannot enter certain regions of a cell membrane because why?
Description : The basic structure of cell membranes (a) Is a lipid bilayer that serves as a barrier to water soluble molecules (b) Differs ultra structurally for internal and external membranes ... dispersed within a protein bilayer (d) Is visualised as bilaminar structure with transmission electron microscopy
Last Answer : Ans:(a)
Description : Bile, an emulsifier liquid, is made by the liver and later stored within the gallbladder and released in the duodenum. Bile is composed of bile salts, cholesterol and bile pigments. ... enzymes that break fats into simpler fatty acids and glycerol. Digestion System - Image Diversity: gallbladder
Last Answer : What is the adnexal organ of the digestive system in which bile is stored?
Description : Cell membranes a. consist almost entirely of protein molecules b. are impermeable to fat-soluble substances c. in some tissues permit the transport of glucose at a greater rate in the presence of ... to electrolytes but not to proteins e. have a stable composition throughout the life of the cell
Last Answer : in some tissues permit the transport of glucose at a greater rate in the presence of insulin
Description : Only two of the following Statements accurately describe what happens in the mouth. 1. 2. 3. 4. Amylase breaks down large starch molecules into smaller maltose molecules. Chewing increases the surface area of food for digestion. Saliva emulsifies ... ? (a) 1 and 2 (b) 2 and 3 (c) 3 and 4 (d) 1 and 4
Last Answer : (a) 1 and 2
Description : Food digestion is conversion of (a) Macromolecules to micromolecules (b) Non diffusable to diffusable molecules (c) Insoluble to soluble (d) All
Last Answer : (d) All
Description : Which of the following is an example of residual solvent? A. Starting materials B. Methanol C. Degradation products D. Heavy metals
Last Answer : A. Starting materials