Lesson 1 - Review

Sun

The origin of NRG

The Law of Conservation of NRG (Endothermic)

1. If a chem system (reaction inside) gains NRG, the surroundings (outside) lose NRG
2. Energy/heat ------ the chem system and there is an increase in chem EP
3. Less NRG is released by bond formation than whats consumed by bond breakage

The Law of Conserevation of NRG (Exothermic)

1. If a chem system (reaction inside) loses NRG, the surroundings (outside) gain NRG
2. Energy/heat ----- the chem system and there is a decrease in chem EP
3. More NRG is released by bond formation than whats consumedby bond breakage

Endothermic

Is photosynthesis endothermic or exothermic?

Exothermic

Is cellular respiration endothermic or exothermic?

Exothermic

Is a hydrocarbon combustion reaction endothermic or exothermic?

Photosynthesis Reaction

NRG + 6CO2(g) + 6H2O(l) - C6H12O6(s) + 6O2(g)

Cellular Respiration Reaction

C6H12O6(s) + 6O2(g) - 6CO2(g) + 6H2O(l) + NRG

Hydrocarbon Combustion Reaction

CxHy + O2(g) - CO2(g) + H2O(g)

Closed System

1. Matter cannot enter/exit however NRG can
2. This is how in certain reactions water is liquid

Open System

1. Matter and NRG can enter/exit
2. This is how in certain reactions water is gas

Isolated System

1. Neither matter or NRG can enter/exit
2. This does not exist

Cellular respiration, photosynthesis

Which of the following is a closed system: Cellular respiration, photosynthesis, hydrocarbon combustion

Hydrocarbon combustion

Which of the following is an open system: cellular respiration, photosynthesis, hydrocarbon combustion

The reaction is an open system

If you were doing a test and the question does not mention what kind of system the reaction is, what should you assume?

The reaction is a closed system

If you were doing a test and the reaction was a combustion reaction, however the question mentions nothing regarding the systems except a bomb calorimeter what should you assume?

Kinetic NRG (EK)

1. Motion of an entity (can be translational, rotational, vibrational)
2. EK = Q

Chem Potential NRG (EP)

NRG stored in bonds of substances and relative intermolecular forces

Thermal NRG

1. Total EK of all particles of a system (reaction)
2. As temp increases, this increases
3. The greater this is, the more mass, the more particle movement, the more heat, the more change in temp, and the more heat capacity
4. Q = mc△t

Temperature

1. Measure of the average EK of particles in a system (reaction)
2. DOES NOT = NRG

Heat

1. The transfer of thermal NRG
2. Not possessed by system (reaction) but flowing between the system (reaction)

Kinetic Molecular Theory

1. Particles are in constrant, random motion (temp directly related)
2. The higher the temp, the greater the motion
3. The lower the temp, the lesser the motion
4. A change in temperature is = to a change in kinetic NRG

Specific Heat Capacity

How much NRG is required to raise the temp of a subtance by one gram

The substance is water

If you were doing a calculation question on a test, and the substance is not mentioned, but you needed to know the substance to find the right heat capacity for the right answer, what would you assume?