Description : Elements are made of -----? A. Atoms (Answer) B. Molecules C. H2O D. Compounds
Last Answer : A. Atoms (Answer)
Description : The substances which are capable of ab- sorbing combined water or elements of water from molecules of compounds are called?
Last Answer : Dehydrating agent
Description : Which of the following compounds has the least tendency to form hydrogen bonds between molecules ?
Last Answer : Which of the following compounds has the least tendency to form hydrogen bonds between molecules ? A. `NH_(3)` B. `H_(2)NOH` C. `HF` D. `CH_(3)F`
Description : Do polar compounds have stronger or weaker attractions between molecules?
Last Answer : Polar compounds have stronger attractions between molecules.
Description : Which of the following is false? (1) Most carbon compounds are poor conductors of electricity. (2) The force of attraction between carbon molecules is not very strong. (3) The atomic number of carbon is 6. (4) The earth’s crust has about 2% carbon in the form of minerals.
Last Answer : (4) The earth’s crust has about 2% carbon in the form of minerals.
Description : The correct sequence for the manufacture of molecules/organic compounds on the primitive earth is (a) NH3, nucleic acid, protein and carbohydrate (b) protein, carbohydrate, water and nucleic acid (c) NH3, protein, carbohydrate and nucleic acid (d) NH3, water, nucleic acid and protein.
Last Answer : (d) NH3, water, nucleic acid and protein.
Description : Which of the following compounds have planar molecules? (a) 1,3-Butadiene (b) Dimethyl ether (c) 1-Butene (d) Allene
Last Answer : 1,3-Butadiene
Description : Which of the following is a true statement? (a) All chiral molecules possess a plane of symmetry. (b) All achiral molecules are meso. (c) All molecules which possess a single asymmetric center of the S configuration are levorotatory. (d) A mixture of achiral compounds will be optically inactive
Last Answer : A mixture of achiral compounds will be optically inactive
Description : Which of the following compounds have planar molecules? (a) ethyl alcohol (b) formaldehyde (c) diethyl ether (d) 1,3-butadiene
Last Answer : 1,3-butadiene formaldehyde
Description : Pick out the wrong statement. (A) Molecules with symmetrical arrangements (e.g. CH4 or CCl4) are non polar (B) Generally, non-polar compounds are chemically inactive, conduct electricity poorly and do not ionise (C) Most of the hydrocarbons are non-polar (D) None of these
Last Answer : (D) None of these
Description : Those substances which have so far not been resolved by any means into other substances of simpler form are called A. elements B. compounds C. atoms D. molecules
Last Answer : Answer: A
Description : A family of organic compounds whose molecules will add water under an acid catalysis and change into alcohols are the: w) alkenes x) alkanes y) aromatic hydrocarbons z) cycloalkanes
Last Answer : ANSWER: W -- ALKENES
Description : Ketones are organic compounds. Name the functional group that all ketone molecules contain.
Last Answer : ANSWER: CARBONYL GROUP pr C DOUBLE BOND O
Description : Consider the following statements: 1. The atmosphere of the primitive earth was reducing 2. The primary source of energy for the chemosynthetic reactions on earth that led to the origin of life was the solar energy 3. Liquid water did not ... 1 and 2 (b) 1 and 4 (c) 1, 2, and 3 (d) 1, 3, and 4
Last Answer : Ans:(d)
Description : The average kinetic energy of the molecules of a body determines? A. heat B. temperature (Answer) C. internal energy D. none
Last Answer : B. temperature (Answer)
Description : The blueness of the sky is mainly due to -------? A. The scattering of sunlight by air molecules (Answer) B. The presence of water vapor C. Absorption of blue light by the air D. Emission of blue light by the atmosphere
Last Answer : A. The scattering of sunlight by air molecules (Answer)
Description : Nuclear radiation is emitted by those elements whose: A. molecules are stable B. molecules are unstable C. nuclei are stable D. nuclei are unstable (Answer)
Last Answer : D. nuclei are unstable (Answer)
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 : The increasing vapor pressure caused by heating a liquid is due to------? A. increase inter-molecular interactions B. increasing potential energy of molecules C. increasing kinetic energy of molecules (Answer) D. decreasing surface tension
Last Answer : C. increasing kinetic energy of molecules (Answer)
Description : Rate of evaporation of petrol is greater than that of water at room temperature because: A. petrol molecules do not have any hydrogen bond (Answer) B. petrol is an organic compound C. water molecules have small size D. petrol molecules have greater size
Last Answer : A. petrol molecules do not have any hydrogen bond (Answer)
Description : Honey contain glucose and fructose along with some other ingredients, it has greater viscosity due to------? A. hydrogen bonding B. irregular shape of the molecules C. irregular shape of the molecules and strong inter-molecular forces (Answer) D. greater molecular size
Last Answer : C. irregular shape of the molecules and strong inter-molecular forces (Answer)
Description : In humans , most nutrient molecules are absorbed by the ? A. Small intestine (Answer) B. Stomach C. Liver D. Large intestine E. None of these
Last Answer : A. Small intestine (Answer)
Description : Use the information and data given below to answer the questions Stronger intermolecular forces result in higher boiling point Strength of London forces increases with the number of electrons in the molecule ... here? (c) Why is the boiling point of HF highest while that of HCl lowest?
Last Answer : Ans :( a) In the molecules HCl, HBr and HI, dipole-dipole interaction and London forces are present. (b) Dipole moment of HCl > HBr > HI but boiling point of HCl < HBr