Chemistry-quantitive Chemistry Flashcards
How do you calculate the relative formula mass of a substance
Relative formula mass is is the sum of relative atomic masses in the substance
How do you calculate the percentage mass of a element in a compound
Percentage mass = Number of atoms/Relative formula mass of the compound, multiplied by 100
What is the value of the Avogadro constant
6.02 x 10 to the power 23
What is the formula that relates the number of moles in a substance to mass and relative formula mass
number of moles = mass ÷ relative formula mass
What is the conservation of mass
The conservation of mass is the idea that mass is neither created or destroyed during a chemical reaction
What is meant by the term “limiting reactant”
A reaction is finished when all of one of the reactants are used up. The other reactant has nothing left to react with and is said to be in excess. The reactant that is all used up is said to be the limiting reactant
What is concentration
Concentration is the amount of solution in a given amount of area. The more concentrated a solution the more particles in its given volume
How do you measure the mass or volume of a reactant/product
you can use a gas syringe or scale to see how the reaction changes as it progresses
What is the word equation for concentration
concentration = amount/volume
What is a mole
A mole is a unit for the amount of a substance
How do you solve questions relating to reacting masses
You calculate the relative formula mass of substances involved in the reaction and then scale down to the required mass
How do you calculate the percentage yield
Percentage yield = Actual yield/Theoretical yield
How do you calculate the atom economy
Atom economy = Relative formula mass of an atom in products/relative formula mass of reactants
How much space does 1 mole of gas take up
1 mole of gas = 24dm cubed
In terms of concentration, how do you calculate number of moles
number of moles = concentraion x volume
