Chemical Equations and Reactions Flashcards
Molecule
An aggregate of at least 2 atoms of a definite arrangement held together by chemical forces
- Diatomic: only 2 atoms
- Polyatomic: more than 2 atoms
Molecular mass
Sum of atomic masses in a molecule e.g. H2O = 18
Mole
Relates mass of a substance to a number of atoms/molecules present. A unit to count numbers of particles
1 mole = 6.022 x 1023
Chemical reactions
A process in which a substance or substances is/are changed into one or more new substances. A chemical equation uses chemical symbols to show what happened during a chemical reaction.
Molar mass
The mass in grams of 1 mole of molecules or 1 mole of atoms. E.g 1 mole of C=12grams
Molecular formula
shows the exact no. of atoms of each element in a molecule C6 = 6 carbons
How to balance chemical equations
- 1 in front of most complicated molecule
- Leave oxygen last *
Balance equation with smallest whole number
- Leave oxygen last *
solution
Homogeneous mixture of 2 or more substances can be formed in any state of matter that is they may be solid liquid or gas
concentration
The amount of soluble present in a given amount of solvent, or a given amount of solution
Dilute
Contains relatively little solute in a large quantity of solution
Concentrated
Contains relatively large amount of solute in a given quantity of solution.
Calculating the weight/volume%
Grams of solute/100ml of solution
Isotonic
A solution that has the same concentration of solute as in our blood 0.9% ACL, 5%glucose
Molarity
no moles of a solute per litre of a solution
Osmosis
Movement of water across a semi permeable membrane
Hypotonic
contains fewer solutes (such as salt and other electrolytes) than is found in normal cells and blood
Hypertonic
contains more solutes (such as salt and other electrolytes) than is found in normal cells and blood
