Description : A zwitterion is (a) an ion that is positively charged in solution (b) an ion that is negatively charged in solution (c) a compound that can ionize both as a base and an acid. (d) a carbohydrate with an electrical charge.
Last Answer : a compound that can ionize both as a base and an acid
Description : At a pH below the isoelectric point, an amino acid exists as (A) Cation (B) Anion (C) Zwitterion (D) Undissociated molecule
Last Answer : Answer : A
Description : Diamond has each of the following properties except: w) extreme hardness x) ability to conduct electricity y) high melting point z) tendency to burn in air
Last Answer : ANSWER: X -- ABILITY TO CONDUCT ELECTRICITY
Description : An aqueous solution of glycine is neutral because of the formation of : (a) Carbanion (b) Zwitterion (c) Carbonium ions (d) Free radicals
Last Answer : Zwitterion
Description : Which of the following is not a characteristic of organic compounds? (a) They usually have low melting points. (b) They usually are only slightly soluble or insoluble in water. (c) If water ... they seldom conduct an electric current. (d) Bonds which bind the atoms together are nearly always ionic.
Last Answer : Bonds which bind the atoms together are nearly always ionic.
Description : For a substance, density, solubility and melting point are examples of: w) physical properties x) amorphous properties y) chemical properties z) potential properties
Last Answer : ANSWER: W -- PHYSICAL PROPERTIES
Description : Most covalent compounds (a) Behave like electrolytes in the molten state (b) Have high melting and boiling points (c) Are hard substances because of strong covalent bonds (d) Are more soluble in non-polar solvents than in polar solvents
Last Answer : Ans:(d)
Description : Reaction between X and Y forms compound Z. X loses electron and Y gains electron. Which of the following properties is not shown by Z? A) Has high melting point B) Has low melting point C) Conducts electricity in molten state D) Occurs as solid
Last Answer : B) Has low melting point
Description : Refractory metals are known for which of the following properties: w) lack of chemical reactivity x) low density y) high melting point z) high thermal conductivity
Last Answer : ANSWER: Y -- HIGH MELTING POINT
Description : As one goes across a period in the periodic table, the ionization energy generally increases for one of the following reasons. Is it because of the increasing w) atomic radius x) melting point y) nuclear charge z) density
Last Answer : ANSWER: Y -- NUCLEAR CHARGE
Description : A Zwitterion is (A) Positive ion (B) Negative ion (C) Both (A) and (C) (D) None of these
Last Answer : Answer : C
Description : At isoelectric pH, an amino acid exists as (A) Anion (B) Cation (C) Zwitterion (D) None of these
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 : How could you use the physical properties of melting and boiling point to identify a substance?
Last Answer : The melting point and boiling point of a pure substance are veryspecific numbers; knowing these allows you to narrow down thepossible identity of the substance.
Description : Nylon-66 compared to nylon-6 has (A) Lower melting point (B) More abrasion resistant properties (C) Higher hardness (D) All (A), (B) and (C)
Last Answer : (C) Higher hardness
Description : Which of the following properties of a solid is not dependent on crystal imperfection? (A) Ductility (B) Semi-conductivity (C) Melting point (D) Yield stress
Last Answer : (C) Melting point
Description : Pick out the wrong statement pertaining to the properties of glasses. Glasses generally have (A) High electrical insulation properties (B) Sharp melting points (C) Low co-efficient of thermal expansion (D) Compressive strength much greater than their tensile strengths
Last Answer : (B) Sharp melting points
Description : Metals have ______. (1) High melting and boiling point (2) Low melting and boiling point (3) High melting and low boiling point (4) Low melting and high boiling point
Last Answer : (1) High melting and boiling point
Description : In arc welding, Argon is used because of its - (1) Low reactivity with metal (2) Ability to lower the melting point of the metal (3) High flammability (4) High calorific value
Last Answer : (1) Low reactivity with metal Explanation: In arc welding, Argon is used as a shielding gas because it is chemically inert and forms no compounds. At the high temperatures that welding requires, the ... to brittle welds and instability in the welding arc. So,argon and other inert gases are sprayed.
Description : Although Diamond is Covalent, yet it has high melting point. Why?
Last Answer : Ans. All the four valencies are satisfied by carbon.
Description : AlF3 is a high melting point solid whereas SiF4 is a gas?
Last Answer : Ans.AlF3 is an ionic solid due to large difference in electro negativity of Al and F whereas SiF4 is a covalent compound and hence only weak Vander Waals force exists between the molecules.
Description : Amino acids have relatively high melting point as compared to corresponding haloacids. Explain.
Last Answer : Ans: Amino acids have relatively higher m.p as compared to corresponding haloacids. We know that amino acids have amino (basic) group and carboxylic (acid) group. A proton which comes from ... form amino acids become crystalline solids and due to this salt like structure show higher melting point.
Description : In arc welding, Argon is used because of its (1) Low reactivity with metal (2) Ability to lower the melting point of the metal (3) High flammability (4) High calorific value
Last Answer : Low reactivity with metal
Description : Why is melting wax a physical properties of flammability is a chemical property?
Last Answer : Melting is a physical property because the chemical composition remain unchanged.Flammability is a chemical property because involve a combustion reaction.
Description : Agar is used for solidifying culture media because A-it does not affect by the growth of bacteria B-it does not add to the nutritive properties of the medium C-the melting and solidifying points of agar solution are not the same D-all of the above
Last Answer : all of the above
Description : Consider the following statements: 1. When a nerve fibre is stimulated, a profound change is produced in the electrical properties of surface membrane and in steady potential. 2. Upon excitation, the resting potentialis suddenly changed. 3. It is due ... 1, 2, 3 (b) 2, 3 (c) 1, 2, 3, 4 (d) 1, 2, 4
Description : How does the melting point of propane and ethane compare? (a) the melting point of propane is greater. (b) the melting point of ethane is greater. (c) the melting points are within 5°C of one another. (d) no relationship exists among these alkanes and their melting point
Last Answer : the melting point of ethane is greater.
Description : For a point charge to feel a net force in a homogeneous magnetic field, which one of the following statements is true? The charge must: w) move parallel to the magnetic lines of flux x) have a component of its motion perpendicular to the lines of flux y) be stationary z) be a positive charge
Last Answer : ANSWER: X -- HAVE A COMPONENT OF ITS MOTION PERPENDICULAR TO THE LINES OF FLUX
Description : Consider a neutral conducting sphere. A positive point charge is placed outside the sphere. The net charge on the sphere is then, (A) negative and distributed uniformly over the surface of the sphere ... (C) negative and distributed non-uniformly over the entire surface of the sphere (D) zero
Last Answer : (D) zero
Description : Baryllium Sulphate is less soluble in water due to (1) High inflammable energy (2) Low Energy of dissociation (3) Low inflammable energy (4) Lonic band
Last Answer : High inflammable energy
Description : What is the melting point of water ?
Last Answer : The melting point of water is 0 সেল C
Description : Isoelectric pH of an amino acid is that pH at which it has a (A) Positive charge (B) Negative charge (C) No net charge (D) All of these
Description : (4) less soluble in blood than nitrogen at high pressure Explanation: Deep-sea divers have their oxygen supply mixed with helium in order to avoid the toxic nature of oxygen under extreme pressures. The ... blood which blocks blood flow as the diver comes to the surface of the sea from underwater.
Last Answer : The chemical bahaviour of an atom depends upon - (1) the number of protons in its nucleus (2) the number of neutrons in the nucleus (3) the number of electrons orbiting around the nucleus (4) the number of nucleons in the nucleus
Description : Helium is added to the oxygen supply of deep sea divers because it is (1) less poisonous than nitrogen (2) Lighter than nitrogen (3) Readily miscible with oxygen (4) less soluble in blood than nitrogen at high pressure
Last Answer : less soluble in blood than nitrogen at high pressure
Description : What is the melting point of titanium ?
Last Answer : Titanium has a melting point of 1677 degrees Celsius.
Description : What is the melting point of scandium ?
Last Answer : Scandium has a melting point of 1541 degrees Celsius.
Description : What is the melting point of helium ?
Last Answer : The melting point of helium is minus 272 degrees Celsius.
Description : What is the melting point of hydrogen ?
Last Answer : The melting point of hydrogen is minus 259 degrees Celsius.
Description : What is the melting point of calcium ?
Last Answer : The melting point of calcium is 848 degrees Celsius.
Description : What is the melting point of potassium ?
Last Answer : The melting point of potassium is 64 degrees Celsius.
Description : What is the melting point of argon ?
Last Answer : Argon melting point - 189 degrees Celsius.
Description : What is the melting point of chlorine ?
Last Answer : Melting point of chlorine - 101 degree Celsius.
Description : What is the melting point of sulfur ?
Last Answer : The melting point of sulfur is 113 degrees Celsius.
Description : What is the melting point of phosphorus ?
Last Answer : The melting point of phosphorus is 44 degrees Celsius.
Description : What is the melting point of silicon ?
Last Answer : Silicon has a melting point of 1420 degrees Celsius.
Description : What is the melting point of aluminum ?
Last Answer : Aluminum has a melting point of 660 degrees Celsius.
Description : What is the melting point of magnesium ?
Last Answer : Magnesium has a melting point of 650 degrees Celsius.
Description : What is the melting point of sodium ?
Last Answer : The melting point of sodium is 98 degrees Celsius.
Description : What is the melting point of neon ?
Last Answer : Neon melting point - 249 degrees Celsius.
Description : What is the melting point of fluorine ?
Last Answer : Melting point of fluorine - 220 সেল C.