C3-quanititive Chemistry Flashcards
What is the triangle for mass,mol,mr
Mass
(g)
———-
Mr. X Mole
(g/mol). (Mol)
Triangle for mass of solute, volume and concentration
Mass of solute
(g)
———————
Volume x concentration
(dm ³). (g/dm ³)
Triangle, for number of moles concentration and volume
Number of moles
(Mol)
————————-
Concentration x volume
(Mol/dm ³) (dm ³)
Equation for percentage yield
Percentage yield = actual yield / predicted, yield x100
Equation for atom economy
Atom economy = mass of useful / mass of all products x100
Definition of relative formula mass
The mass of a molecule
Definition of atomic mass number
Number of protons, plus number of neutrons
Definition for conservation of mass
The law of conservation of mass states that no atoms are lost or made during a chemical reaction to the mass of the products equals the mass of the reactants
Definition of a mole
The number of atoms molecules or ions in a mole of a given substance is Avagardo’s constant, which is 6.02×10^23 per mole.
Definition of volume of gas
The volume of one mole of any gas at room, temperature and pressure 20°C, and 1 atm pressure is 24 dm ³
Definition of limiting reactant
Is the reactant I get to use a fast in reaction this is the reactant that is not in excess
Definition of concentration
A measure of the mass or amount of solute dissolved in a given volume of solvent or solution
How much of a substance you have per unit volume?
Definition of uncertainty
The uncertainty of a measuring instrument is estimated as plus or minus half the smaller scale division
Definition of percentage yield
The percentage yield shows how much product is obtained, compared to the maximum possible mass
Definition of atom economy
The atom economy of a reaction gives the percentage of atoms in reactants that form a desired product
How do you convert cm³ into dm ³
You divided by 1000
How do you convert dm³ into cm³
You multiplied by thousand
What is 1 dm cubed equal to in centimetres cubed
1000 cm³
How can you increase the concentration of an acqueous (dissolved in a liquid) solution?
Adding more, so you and dissolving in the same volume of its solution
Evaporating of some of the water from the solution, so you have the same mass of solute in a smaller volume of solution
What is the percentage composition?
The amount of an element in a compound is called its percentage composition. It can be calculated using the mass of an element in the compound and the MR of the compound.
What is the equation for percentage composition?
% composition= AR of element / total, MR of compound x100
How do you workout the relative formula mass of a compound or element
Ignore any coefficient
Look at the periodic table to see what the massive number is Time is it by whatever the subscript is
What is titration?
Titration is used to find the unknown concentration of a solution. It’s a neutralisation reaction.
Write the step to step method for titration
- collect your equipment.
- You will need a burette. Pipette conical flask. Funnel. White tile. (To see colour chnage) Substance of a known concentration and substance of an unknown concentration.
- At the unknown concentration acid into the Bure, making sure the tap is closed. Record the initial volume
- Use pipette to measure a fixed volume of the non-concentration alkali into the conical flask on top of the white tile.
- Add a few drops of methyl orange into the alkali
- Open the taps and gradually let the acid flow into the alkali drop by drop. whilst swirling the conical flask.
- Do this until the alkali turns colourless
- Note the final volume of the acid when the endpoint is reached.
- Use the equation concentration equals number of moles /volume
1:1 ratio
How do you know what one mole of an element element weighs
One more of an element is the same as its massive number in grams
What is the name of the man who invented the idea of the conservation of mass?
Antoine, Lavoisier
How to workout the mass of a product using the ratio?
Use the given mass of the reactants and divide by the MR to get the moles
Depending on what the ratio is do that to the number of moles u got. Use the mole and the Mr find the mass.
Where is the step-by-step guide to balance a symbol equation, using the stoichiometric ratio?
Step one divide Mass, by M.O to calculate the number of moles of each
Step two divided number of moles by the smallest to determine the ratio
Step three, the molar ratio is equal to the coefficient in the equations
What is the symbol formula for glucose?
C (s 6) H (s 12) O (s 6)
How do we know if something is a limiting reactant?
Is the number of moles of a reactant is less than the ratio. Then we would cold is the limiting reactant.
The limiting reactant will limit how far the reaction goes
The limiting reactant itself will be fully, used up
The reaction will only go as far as the number of moles of the limiting reactant allows
We can calculate which reacting is limiting using mole equation
What is one cubic decimetre equal to?
1 LItre
What is the solute
The substance that is dissolved
And if we double the volume, what happened to the concentration
We half it
If we half the volume, what happened to the concentration?
Double it
How to workout the concentration using moles?
Step one, find the mould using more equals mass divided by mr
Step to find the concentration from the mall. Using concentration equals number move divided by volume.
Give three potential reasons as to why the percentage yield less than 100%
Losing reacted by transfer
Side reactions may occur
Incomplete reaction
Hey, give me a reason by reactions look like they have gained extra mass
If I gas has been absorbed/if you’re reacting combined with a gas
Give a reason why reactions look like they have lost mass
A gas may have been produced as a product
I define thermal decomposition
Where are compound breaks down into simpler substances when heated
Define excess
When a reactant is present in a large amount than is needed to complete the reaction
Nanograms (ng) into grams
n x 10 ^-9
micrograms (um) into grams
n x10 ^-6
Milligrams (mg) into grams
n x 10^-3
Kilograms (kg) into grams
N x 10 ^3
Tonnes (T) / megagrams (Mg)
n x 10^6
Symbol for ammonia and methane
NH3
CH4
What is Avagard’s constant used for?
To work out the mass of a single atom, iron a molecule
How to work out a date that mass one atom, and a molecule
Simply divide the MR buy avocados, constant
What does student heater the crucible at the end of the reaction? What could a student do to make sure that we actually need to complete
Let the crucible cool down
Weigh it again
REMMEBER GASSES ARE ALWAYS DIATOMIC SO ADD SMALL 2
OKAY
How to work out the relative atomic mass when given difference percentages of differenr isotopes
Times each percetage by each small (mass) number on wach symbol. Add them all up. Divide by a 100
