Thermodynamics only

Question 1

What are the other types of exothermic reactions

Answer 1

When a solvent dissolves, there are water molecules that are attracted to the positive and negative charged ions of the solvent, and therefore makeshift bonds are formed and they surround the solute or ions, therefore the formation of these bonds produces HEAT

THEREFORE WHENEVER YOU GET A QUESTION THAT ASKS ABOUT HEAT RELEASE OF WATER YOU NEED TO MENTION THIS

Question 2

CHANGES OF STATE
MELTING AND EVAPORTAION ARE?

freezing and condensation are??

Answer 2

these are endothermic as they absorb energy

these are exothermic as they release heat to get colder therefore they remove energy.

Question 3

can we measure enthalpy

Answer 3

no but we can measure the change in enthalpy

Question 4

what is state function (from hess law note)

Answer 4

it is that the enthalpy is independent of the systems history or how it was formed

Question 5

enthalpy of formation is?

Answer 5

the enthalpy of elements as they exist in nature at standard conditions which are 25 degrees and 100kpa reacting to give one mole of a compound

EX

element + element = compound

Question 6

WHY ARE BOND ENTHALPIES AND HESS LAW LESS ACCURATE THAN FIRST CALCULATING HEAT RELEASE OVER MOLES

Answer 6

This is becaues bond enthalphies are very average values and only provide a rough estimate\

hess law assumes that the reaction occurs under standard conditions and neglects any other conditions

Question 7

define calorimetry

Answer 7

calorimetry is the measure of the amount of thermal energy transferred in a chemical or physical process.