semester 1 fast recap

Question 1

lattice enthalpy

Answer 1

the enthalpy change when one mole of ionic solid is formed from its gaseous ions, under standard conditions.

Question 2

example of lattice enthalpy

Answer 2

Na+(g) + Cl-(g) –> NaCl(s)

Question 3

enthalpy of atomisation

Answer 3

the enthalpy change when one mole of gaseous atoms is formed from the element in its standard state under standard conditions

Question 4

example of enthalpy of atomisation

Answer 4

Na(s) –>. Na(g)

Question 5

Enthalpy affinity

Answer 5

the enthalpy change when one mole of electrons is added to one mole of gaseous atoms, under standard conditions

Question 6

Example of enthalpy affinity

Answer 6

cl(g) + e- –> Cl-(g)

Question 7

enthalpy change of formation

Answer 7

the enthalpy change when 1 mole of a compound is formed from its elements in their standard states, under standard conditions. (298 K or 25oC and 1atm pressure

Question 8

enthalpy change equation

Answer 8

bonds broken-bonds formed

Question 9

percentage yield equation

Answer 9

actual moles/theoretical moles x 100

Question 10

percentage error equation

Answer 10

uncertainty of apparatus x no. of readings / quantity x 100

Question 11

rate =

Answer 11

conc/time

Question 12

% by mass equation

Answer 12

total mass of substance / mr of substance x 100