Chemistry A Level
Equations (Edexcel)
questions and answers
2025(passed)
Avogadro Constant - answer no. of moles = no. of
particles/Avogadro constant
Death Bed Equations - answer moles (mol) = mass
(g)/mr (g mol-1)
Concentration (x2) - answer conc. = mol/vol
conc. = mass/vol
Gas Volume - answer no. of moles = vol/molar gas
vol
Ideal Gas Equation - answer PV = nRT
Percentage yield - answer % yield = (actual
yield/theoretical yield) x 100
, Atom Economy - answer atom economy (%) = (mr
of desired products/ total mr of all products) x 100
1 m3 = - answer 1000 dm3
1000 dm3 - answer 1000000 cm3
Heat of Reaction - answer Q = mc change in temp.
Enthalpy Change of Reaction - answer Enthalpy
change of Reaction = sum of bond enthalpies of
reactants - sum of bond enthalpies of products
Rate of reaction - answer rate of reaction = change
in conc. of reactant/product/time
Percentage uncertainty - answer Percentage
uncertainty = uncertainty/reading x 100
Partial pressure - answer Partial pressure = mole
fraction x pressure
Mole fraction - answer Mole fraction of gas A =no.
of moles of gas A/ total no. of moles of gas
Equations (Edexcel)
questions and answers
2025(passed)
Avogadro Constant - answer no. of moles = no. of
particles/Avogadro constant
Death Bed Equations - answer moles (mol) = mass
(g)/mr (g mol-1)
Concentration (x2) - answer conc. = mol/vol
conc. = mass/vol
Gas Volume - answer no. of moles = vol/molar gas
vol
Ideal Gas Equation - answer PV = nRT
Percentage yield - answer % yield = (actual
yield/theoretical yield) x 100
, Atom Economy - answer atom economy (%) = (mr
of desired products/ total mr of all products) x 100
1 m3 = - answer 1000 dm3
1000 dm3 - answer 1000000 cm3
Heat of Reaction - answer Q = mc change in temp.
Enthalpy Change of Reaction - answer Enthalpy
change of Reaction = sum of bond enthalpies of
reactants - sum of bond enthalpies of products
Rate of reaction - answer rate of reaction = change
in conc. of reactant/product/time
Percentage uncertainty - answer Percentage
uncertainty = uncertainty/reading x 100
Partial pressure - answer Partial pressure = mole
fraction x pressure
Mole fraction - answer Mole fraction of gas A =no.
of moles of gas A/ total no. of moles of gas
