Stoichiometry Flashcards
What are coefficients?
Numbers at the start that indicate the relative numbers of molecules involved in the reaction
What changes when balancing equations?
The coefficients, NEVER the subscripts
What are combination reactions?
- 2 or more substances react to form 1 product
- Typically to form a compound
What are decomposition reactions?
A single eat ant breaks apart to form 2 or more products
What are combustion reactions?
Involve O2 as a reactant and CO2 as a product
What are single displacement/substitution reactions?
Where a more reactive element displaces a less reactive one
What is a double displacement reaction?
2 compounds exchange ions to form different compounds
What are redox reactions?
Where there is a change in the oxidation number of the element, usually by the transfer of electrons to different elements or sites within a compound
What is the formula mass of sulphuric acid?
H2SO4 2 x 1 \+ 1 x 32.1 \+ 4 x 16 = 98.1 amu
What is Avagadro’s number?
6.022 x 10²³
How do you calculate the number of moles?
Mass (g) / molar mass (g/mol)
What is the theoretical yield?
The quantity of product formed when all the limiting reactant is used up in the reaction
How do you calculate percentage yield?
Actual yield / theoretical yield x 100%
What is molarity?
No of moles of solute per litre (1000ml) of solution
How do you calculate molarity?
Moles of solute / litres of solution
