introduction to chemical energy

Question 1

if q<0 then…

Answer 1

heat is released to the surrounding therefore the system is EXOTHERMIC

Question 2

if q>0 then…

Answer 2

heat is absorbed to the system therefore the system is ENDOTHERMIC

Question 3

if work is done by the surrounding…

Answer 3

then W is positive. This is a CONTRACTION

Question 4

if work is done by the system…

Answer 4

then W is negative. This is an EXPANSION

Question 5

WORK=

Answer 5

Pressure * ΔVolume

Question 6

The First Law of Thermodynamics

Answer 6

ΔU = q + W

ΔU = ΔH - PΔV

Question 7

STATE FUNCTIONS???

Answer 7

A state function is a property of the system that is determined by the state of
the system, independent of how the system got to that state.

Question 8

ENTHALPY???

Answer 8

Enthalpy, H is amount of heat transferred under constant pressure conditions

Question 9

n(gas)

Answer 9

This is the sum of the moles of product gases minus the sum of the moles of the reactant gases
e.g.
2 C2H6(g) + 7 O2(g) → 4 CO2(g) + 6 H2O(l)
ΔH°= -3119 kJ

n(gas): n(C02) - [n(C2H6)+n(O2)]