Unit3- Quantative chemistry Flashcards
What is the conservation of mass theory
The total amount of the product is equal to the total mass of the reactants
Why must we balance equations
To make sure the reactant mass and product mass are the same because no atoms are gained or lost in a reaction
Ionic compounds form when metals react with what
Non metals
Metals form ? Ions
Most non metals form ? Ions
Metals form positive ions
Most non-metals form negative ions
How do you work out how many ions metals form?
What doesnt this apply to
Note which group they are in for example Magnesium is in group 2, therefore forms 2+ ions
This doesnt apply to the transition metals
How many ions do group 6 metals lose
How many ions do group 7 metals lose
Group 6 lose -2
Group 7 lose -1
What are the two non metals that have a positive charge
Hydrogen+
Ammonium +
In ionic compounds the charges on the ions have to cancel out to leave ?
An overall charge of 0
What do ionic compounds leave out?
Spectator ions
How would you write
Magnesium nitrate
Mg2+ NO3 -
Mg(NO3)2
Percentage by mass= ?/? X100
Mass of element / total relative formula mass of a compound
X100
What is a mole
A measure of the amount of particles in a substance
One mole of any substance contains the same number of particles. What is this amount? What is it called?
6.02 x 10 to the 23
Avogadro constant
The mass of one mole of a substance is its?
Its relative atomic mass or relative formula mass in Grams
Number of moles= ?/?
Mass of a substance in g / atomic (or formula) mass in g/mol
What is the relative atomic mass symbol
Ar
How do you balance an equation using moles
Work out the amount of moles in each compound, divide by the smallest mole amount, then put it onto the og equation
What is a limiting reactant and excess
When two chemicals react together, one chemical is completely used up during the reaction.
Once one chemical is used up, it stops the reaction going any further. This is the limiting reactant. The other is said to be in excess
What is the concentration of a solution
The mass of a solute in a given volume of soltuion
What is the unit for concentration
g / dm3
Concentration = ?/?
Mass (g) / volume (dm3)
