What element is a required reactant in a combustion reaction?
Oxygen, O2
What are the three types of heat transfer?
radiation, convection, conduction
What are the two chemical products of combustion reaction?
Carbon dioxide and water
What is Law of conservation of energy?
can be neither created nor destroyed.
Define heat?
involves the transfer of energy between two objects due to a temperature difference.
Is the freezing of water an endothermic or exothermic process?
Its exothermic, because energy is removed so molecules can form a solid
Exothermic or endothermic:
Your hand gets cold when you touch ice.
Exothermic: Heat energy leaves your hand and moves to ice.
What is energy?
Capacity to do work or to produce heat.
Which is the system and which is surroundings?
Methane is burning in a Bunsen burner in a laboratory
System: methane
surrounding: everything else around it
Where is chemical potential energy stored?
Inside the chemical bonds
What is Kinetic energy?
energy due to motion of the object and depends on the mass of the object and its velocity.
What is a system?
to focus attention on something
Exothermic or endothermic
The ice gets warmer when you touch it.
Endothermic
Heat energy flows into ice.
What is Potential energy?
energy due to position or composition.
Why is freezing water into ice exothermic?
True or false?
Endothermic Reaction Absorb energy from the surroundings
true
Exothermic or endothermic
Water boils in a kettle being heated on a stove
endothermic
Heat energy flows into water to boil
What is Endothermic Reaction?
Heat flow is into a system.
Exothermic or endothermic
Water vapor condenses on a cold pipe.
Exothermic
the condensed energy changes from gas to liquid
what is an Exothermic Reaction?
Energy flows out of the system.
Which is a system and which is surroundings?
Water drops, sitting on your skin after swimming, evaporate.
System: Water drops
surroundings: Anything around it
Define Surroundings?
include everything but things in a system
True or False?
for expanding gas they must have opposite signs?
True
True or false?
State Function: depends on everything but present state
False
only depends on present state
Exothermic or endothermic.
Ice cream melts.
endothermic.
Heat energy flows into ice for it to melt