C P1 - Quantitative Chemistry Flashcards
What is the law of conservation of mass?
The law of conservation of mass - mass of reactants = mass of products
What is the Avogadro constant?
Avogadro constant states that one mole of any substance will contain the same number of particles, atoms, molecules or ions
How many particles does a mole have?
There are 6.023 x 10^23 particles per mole
How do you calculate the number of moles?
The number of moles = mass divided by relative formula mass (Mr)
How do you calculate concentration?
Concentration = mass divided by volume
What does it mean if a substance has a greater mass?
If a substance has a greater mass, it will have a higher concentration
What does it mean if a substance has a greater volume?
If a substance has a greater volume, it will have a lower concentration
What is a limiting reactant?
A limiting reactant is what limits the amount of product that is made
What is the relative formula mass?
The relative formula mass is the sum of the atomic masses in an equation
What does it mean if the mass has increased during a reaction?
If the mass has increased during a reaction, that means one of the reactants is a gas
What does it mean if the mass has decreased during a reaction?
If the mass has decreased during a reaction, that means one of the products is a gas and it has escaped
What is the yield?
Yield is the amount of product obtained
Why is it not always possible to obtain the calculated amount of a product?
It is not always possible to obtain the calculated amount of a product because either;
- The reaction may not go to completion because it is reversible
- Some of the product may be lost when it is separated from the reaction mixture
- Some of the reactants may react in ways different to the expected reaction
How do you calculate the percentage yield? (%)
Percentage yield is the mass of the product made divided by the maximum theatrical mass and then times the answer by 100
