A) Nitrogen and oxygen B) Oxygen and hydrogen C) Sulphur and oxygen D) Carbon and oxygen
A) X2Y B) XY2 C) X3Y2 D) X2Y3
A) 8 and 2 B) 1 and 3 C) 6 and 2 D) 2 and 3
A) +7 B) -7 C) +8 D) -5
A) Crystallisation B) Evaporation C) Melting D) Sublimation
A) Sulphur B) Argon C) Potassium D) Chlorine
A) Protons between two atoms B) Electrons between two atoms C) Neutrons between two atoms D) Electrons from one atom to another
A) CO2 B) H2O C) NH3 D) NaCl
A) Transfer of electrons between atoms B) Presence of positive ions in a sea of delocalized electrons C) Sharing of electrons between atoms D) Formation of covalent bonds between atoms
A) Water B) Sodium chloride C) Carbon dioxide D) Iron
A) Electronegativity difference between atoms B) All of the above C) Electron affinity of atoms D) Atomic radius of atoms
A) Helium B) Nitrogen C) Oxygen D) Carbon
A) Strong covalent bonds between atoms B) Weak intramolecular forces within molecules C) Weak intermolecular forces between molecules D) Strong electrostatic attractions between ions
A) Ethanol (C2H5OH) B) Methane (CH4) C) Sodium chloride (NaCl) D) Hydrogen peroxide (H2O2)
A) Have fixed positions in a lattice structure B) Have negligible volume compared to the space they occupy C) Are closely packed together D) Have strong intermolecular forces of attraction
A) The density of particles within a gas B) The motion of particles within a gas C) The arrangement of particles within a gas D) The chemical reactions occurring within a gas
A) Digestion of food B) Rusting of iron C) Melting of ice D) Burning of wood
A) Pressure and temperature of a gas B) Volume and number of moles of a gas C) Pressure and volume of a gas D) Temperature and volume of a gas
A) PV = RT B) P = V/nRT C) PV = nRT D) PV = nT
A) Square root of its molar mass B) Pressure C) Volume D) Temperature
A) Atomic mass B) Density C) Number of moles D) Volume
A) Electrons in one atom of a substance B) Particles in one gram of a substance C) Atoms in one mole of a substance D) Moles in one liter of a gas
A) NH3 B) HCN C) H2O D) CO2
A) Large difference in electronegativity B) Both elements are non-metals C) High similarity in electronegativity D) Similar electron affinity values
A) Helium B) Oxygen C) Sodium D) Chlorine
A) They are responsible for the high melting and boiling points of many molecules. B) They form between atoms with similar electronegativity. C) They can be polar or non-polar D) They involve sharing electrons.
A) Covalent bonding B) Hydrogen bonding C) Dipole-dipole interactions D) London dispersion forces
A) They attract each other strongly B) They occupy a significant volume. C) They are constantly in motion. D) They have specific shapes.
A) liquids flow easily and have indefinite shapes. B) solids are rigid and have definite shapes C) gases expand to fill their container. D) all three statements are true.
A) dependent on the container size. B) directly proportional to its temperature C) inversely proportional to its temperature D) constant
A) K B) R C) P D) V
A) wood and oxygen is less than the mass of the products. B) wood decreases, while the mass of the products remains constant. C) wood and oxygen is equal to the mass of the carbon dioxide and water vapor. D) wood and oxygen is greater than the mass of the products.
A) are not needed, only the coefficients are important. B) compounds are ignored. C) elements are used directly. D) reactants and products are used to convert between grams and moles.
A) perform complex mathematical calculations. B) balance the chemical equation first. C) memorize the names of all elements and compounds. D) know the physical properties of all the reactants and products.
A) Carbon dioxide (CO₂) has a constant ratio of carbon to oxygen, regardless of its origin. B) Water (H₂O) always contains hydrogen and oxygen in a 2:1 ratio by mass. C) The color of a compound can vary depending on its source. D) All samples of table salt (NaCl) have the same ratio of sodium to chlorine.
A) 1:2 B) Cannot be determined without additional information. C) 2:3 D) 1:3/2
A) Two molecules of hydrogen react with one molecule of oxygen to form two molecules of water. B) Hydrogen and oxygen react explosively to form water. C) Water can decompose into hydrogen and oxygen under specific conditions. D) 2 grams of hydrogen react with 1 gram of oxygen to produce water.
A) all chemical reactions. B) compounds that can react with each other. C) only elements, not compounds. D) elements that can form more than one compound with another element.
A) the names of the reactants and products B) the order in which the reactants combine. C) the states of matter of the reactants and products. D) the relative amounts of each molecule or atom involved in the reaction.
A) 10 moles B) 2.5 moles C) 5 moles D) Cannot be determined without additional information. |