Chem equations

absolute uncertainty

+-(1/2 x resolution of measuring equipment)

percentage uncertainty

absolute uncertainty/measurement x 100

Energy (Q) /J

m(g) x c (Jkg^-1C^-1) x T(^.C)

No. of moles (n) /mol Molar mass

m/M

no. of moles (n) /mol Concentration

c(moldm^-3) x v(dm³)

Relative abundance (AR)

(AR of isotope 1 x Abundance of isotope 1 + AR of isotope 2 x abundance of isotope 2)/100

Pressure(Pa) x Volume(m³)

n(mol) x R(8.31JK^-1mol^-1) x T(K)

Combustion equation

C_XH_y + (x+y/4)O₂ ——> xCO₂ + y/2H₂O

Enthalpy change (_^H)

-Q(J) / n(mol)

^H reaction

-Σ^Hf(reactants) - Σ^Hf(products) OR Σ^Hc(reactants) - Σ^Hc(products)

Equilibrium constant (Kc)

mole fraction (xA)

number of moles of A /total number of moles of gas

Partial pressure (total)

PA + PB.. etc

Partial pressure of A (pA)

mole fraction A(xA) x total pressure (PT)

Acid + metal →

salt and hydrogen

Acid + base →

salt + water

Acid + Carbonate →

salt + water + carbon dioxide