Chemistry

• In a solution, the substance that does the dissolving is called? Solvent
• Answer: D

  
• A solution that cannot hold any more solute at a room temperature would be a saturated solution
• Answer: A

  
• Answer: C

  
• A supersaturated solution - is a solution that contains more dissolved solute than it would normally hold at a given temperature and pressure.
• A solute is a substance that is dissolved in a solvent to form a solution. In a solution, this component present in a smaller amount, while the solvent is the component present in a larger amount.
• Answer: B

  
• Answer: D

  
• Answer: D

  
• Answer: B

  
• Which of the ff substance cannot be decomposed by ordinary chemical means?

  Answer: Iron

  a.air

  b. water

  c. salt

  d. iron
• A positively-charged ion has more protons than electrons. This ion is also called as cation.
• An anion - is an ion with negative charge, meaning it has more electrons than protons.
• Chemical reaction may involve all of the ff except

  Answer: A

  a.seperation of the molecules in a mixture

  b. breaking down of compounds into elements

  c. combination of atoms of elements to form a molecule

  d. reaction of a compound and an element to form a new compound and a new element
• A substance that gives up hydrogen ions to water to form hydronium ions is called an acid
• Which of the ff elements exists as molecules

  Answer: B

  a.He

  b. H

  c. Ar

  d. Kr
• *Half life of an element*

  Bromine-82 has a half-life of 35.7 hours. How many milligrams of 82Br will remain if 2.30g of 82Br decays for exactly one week?

  Answer: 88.1 mg
• In ionic bonds, electrons are transferred between atoms
• Which of the ff pH values represents the strongest acid?

  Answer: D

  a.12

  b. 8

  c. 7

  d. 2
• Pure substances - are substances that are made up of only one kind of particle and have a fixed or constant structure.
• Phase Changes

  • Freezing: Change of a substance from liquid phase to solid
  • Melting: Change from solid phase to liquid
  • Vaporization: Change from liquid to gaseous form
  • Condensation: Change from gas to liquid form
  • Sublimation: Change from solid to a gas without becoming a liquid
  • Deposition: Change from gas to solid without becoming a liquid
  • Ionization: Change from a gas phase to plasma (ionized particles)
  • Recombination: Change from plasma to gas
• Activation energy - is the energy needed to start a reaction.
• Answer: D

  
• Answer: B

  
• Answer: A

  
• The atomic mass of an element is determined by its total number of? Protons and Neutrons
• Answer: A

  
• Answer: A

  
• Of the ff elements, which is the least common in living organisms?

  Answer: D

  a.Hydrogen

  b. Carbon

  c. Oxygen

  d. Sodium
• Answer: D

  
• During oxidation, molecules lose electrons
• Answer: C

  
• Which of the ff consistently have the highest melting point?

  Answer: B

  a.Metals

  b. Salts

  c. Alkanes

  d. Dipoles
• Under which conditions will real gas behave most likely as an ideal gas? low pressure and high temperature