How much? Flashcards
What is the relative mass of protons and neutrons?
1
What is the atomic number of an atom?
Its number of protons.
What is the mass number of an atom?
Number of protons + Number of neutrons in a nucleus.
What are isotopes?
Atoms of the same element with different number of neutrons.
How do you find the relative formula mass?
Add up the atomic masses of the atoms.
How do you calculate the empirical formula?
- Divide the mass of each element in 100g of the compound by its atomic mass to give the ratio of atoms
- Then convert this to the simplest whole number.
How do you calculate percentage yield?
Amount of product collected
—————————————— x 100
Maximum amount of product possible
What is a reversible reaction?
A reaction in which the products can re-form the reactants.
What is chemical analysis used for?
Identify food additives.
What can paper chromatography be used for?
Detect and identify artificial food colours.
Why are modern instrumental methods useful?
Provide fast, accurate and sensitive ways of analysing chemical substances.
How can compounds in a mixture be separated?
Gas chromatography.
How can the compounds be identified?
Mass spectrometer.
What can the mass spectrometer also do?
Find the relative molecular mass of a compound from its molecular peak?
