2.1 - Atoms Ions And Compounds

Isotopes are atoms of the same element with the same atomic number, but with a different number of neutrons, resulting in a different mass number

The weighted mean mass of an atom of an element, relative to one-twelfth of the mean mass of an atom of carbon-12

The isotopic mass of an isotope relative to one-twelfth of the mean mass of an atom of carbon-12

The weighted mean mass of a molecule of a compound, relative to one-twelfth of the mean mass of an atom of carbon-12

NO3^- SO4^2- CO3^2- OH^- NH4^+

6.02x10^23 particles in one mole

-Moles=mass/Mr -Moles=concentration x volume/1000 (Only when converting dm^3 to cm^3) Moles = volume(dm^3)/24

The simplest whole number ration of atoms of each element present in a compound

The number and type of atoms of each element in a molecule The true number of each atom on the molecule

Substance that contains NO water of crystallisation

Substance that contains water of crystallisation

A solution of known concentration

The reactant that is not in excess

pV = nRT Where: p = pressure in Pa V = volume in m3 T = temperature in K n = moles, mol m = mass, in grams R = ideal gas constant - 8.31 -Only under standard conditions -Temp: 298K/25C Pressure: 100kPa/101kPA

8.31

Experimental mass/theoretical mass x 100

Mr of desired product/Mr of reactants x100

• The higher the atom economy, the less waste product there is • So process is more economically viable for industrial scale manufacture • Helps to preserve raw materials as well

Substance that releases H+ ions in aqueous solution

Substance that releases OH- in aqueous solution

Substance that accepts H+ ions from an acid in aqueous solution

-HCl - Hydrochloric Acid -H2SO4 - Sulfuric Acid -HNO3 - Nitric Acid -H3PO4 - Phosphoric Acid CH3COOH - Ethanoic acid

• NaOH - Sodium Hydroxide • KOH - potassium hydroxide • NH3 - Ammonia

• A strong acid fully dissociates in aqueous solution - A weak acid partially dissociates in aqueous solution