Review for April 8 Chemistry part 2

All atoms of the same element have the same number of

• atomic mass
• atomic number
• number of neutrons plus electrons
• number of protons plus neutrons

Two liquids can be separated by distillation due to a difference

• concentration
• conductivigy
• boiling point
• heat of fusion

Which form of energy is converted to thermal energy when propane burns in the air

• chemical
• electrical
• mechanical
• nuclear

What is the purpose of adding a catalyst to a chemical reaction? How does it make the reaction easier to occur.

• to decrease the activation energy of the reaction
• to decrease the activation energy of the reactants
• to convert solid reactants to liquid reactants
• to provide an alternative reaction way

Look closely. The (s) means solid. The (aq) means liquid. NaCl is salt in water or salt water.

• X is a mixture, Z is a substance
• X is a substance and Z is mixture
• X is an element and Z is a compound
• X is a compound and Z is an element
• Option 4

Which two diagrams represent two different phases of the same compound?

• A andC
• B and D
• B and C
• A and D

Which number represents the activation energy?

• 1
• 2
• 3
• 4

What type of reaction is this

• An endothermic phsycal reaction
• An exothermic physical reaction
• An exotherm chemical reaction
• An endothermic ehcmical reaction

Which substance is a gas at 78 degrees?

• tetrachloromethane
• tetrachloroethene
• 1-bromopropane and tetrachloromethans
• tetrachloroethene and tetrachloromethane

• Reduce the size of the axle running through the center of them motor.
• Increase the number of coils of wire within two sectons of the motor
• Decrease the voltage of the power source being used to operate the motor
• Move the coils farther apart