C6 Chemical Calculations With Mass [Paper 1] Flashcards
What is the conservation of mass?
In a chemical reaction, atoms are not created or destroyed, just rearranged, so total mass before = total mass after the reaction
When a metal form is a metal oxide, why does the mass increase?
Atoms from gas oxygen have been added
When an acid reacts with a metal, why does the mass decrease?
A gas is produced and escapes
What is relative formula mass?
The sum of the relative atomic masses of each atom in a substance
What are the 4 state symbols and what do they stand for?
(S) solid, (l) liquid, (g) gas, (aq) aqueous or dissolved in water
How can you tell when symbol equation is balanced?
The number of atoms of each element is the same on both sides
What is a mole?
Mass of a substance that contains 6.02x10 to the power 23 particles
Give the value for Agrado’s constant
6.02x10 to the power 23
Which formula is used to calculate the number of moles from mass and Mr?
Moles = mass / mr
Which formula is used to calculate the mass of substance from number of moles and Mr?
Mass = moles x Mr
What is a limiting reactant?
The reactant that is completely used up in a chemical reaction
What is a unit for concentration?
g/dm3 or mol/dm3
Which formula is used to calculate concentration from mass and volume?
Concentration (g/dm3) = mass (g) / volume (dm3)
Which formula is used to calculate volume from concentration and mass?
Volume (dm3) = mass (g) / concentration (g/dm3)
Which formula is used to calculate mass from concentration in g/dm3 and volume?
Mass (g) = concentration (g/dm3) x volume (dm3)
How can you convert volume reading in cm3 to dm3?
Divide by 1000
If the amount of solute in a solution is increased, what happens to its concentration?
Increases
If the volume of water in a solution is increased, what happens to its concentration?
Decreases
