Unit 1: Moles and equations Flashcards
Define the following terms: 1. Atom 2. Molecule 3. Ion
- An atom is the smallest part of an element that can exist and still retain the identity of an element.
- A molecule is a group of elements bonded together and the smallest portion of an element or compound can exist alone. 3. An ion is when an atom loses or gains an electron.
What is the relative mass of an atom mean?
is the number of times heavier a particle is than (1/12th) of a carbon 12 atom.
What is the relative molecular mass of a molecule mean?
It is the sum of all the relative atomic masses of the atoms making up the molecule.
when is relative formula mass used?
When the compounds are ionic.
What are isotopes?
It is when the atom has the same number of protons but a different number of electrons.
What is a mole?
It is the number of atoms of an element needed to make up the relative atomic mass in grams.
what is the relationship between mass and mole?
n= m/M
what is Avogadro’s constant?
6.022 x 10^23
What is the purpose of a mass spectrometer?
It is used to find the masses of individual isotopes. it produces a result showing the percentage abundance for each of the isotopes.
What is the relative mass of isotopes?
It is the average values taking into account the percentage abundances for each.
what is meant by molecular formula?
it shows the actual number and types of atoms bonded together.
what is meant by empirical formula?
It is the simplest whole-number ratio of all types of atoms bonded together.
describe how a formula is constructed.
- the reactants and products are written down on the left and right side of the equation correctly.
- the equation is balanced
- state symbols are then inserted into the equation.
how are balanced equations used in mole calculations?
balanced equations tell you the mole ratio. when the mole’s values are plugged it, the ratio is used and the mas is found using the Mr.
what is the volume occupied by any mole of gas at room temperature and pressure?
24 dm3
