What is the mass of the following: Electron? Proton? Neutron?
E = 0.0005, P = 1, N = 1
1 of 18
what is the mass number?
The total number of protons and neutrons in the nucleus of an atom.
2 of 18
Do atoms of the same elment have the same mass number or atomic number?
Atomic number - this is the number of protons (and therefore electrons).
3 of 18
What are isotopes?
Atoms of the same element with different numbers of neutrons.
4 of 18
How do you work you the number of neutrons?
Minus the atomic number (no of protons) from the mass number (number of protons and neutrons in the nucleus)
5 of 18
How many protons, electrons and neutrons are there in the atom flourine?
E = 9, P = 9, N = 10
6 of 18
What is RAM?
Relative atomic mass - Ar
7 of 18
What is a mole?
The RAM of an elemnt in grams - eg a mole of sodium has a mass of 23g
8 of 18
What is RFM
Relative formula mass - Mr. This is all the RAM in a substance added together to find the total of the substance/compound etc.
9 of 18
Calculate the Mr of Calcium Chloride CaCl2
(Ca = 40) + (Cl = 35.5) + (Cl = 35.5) = 111
10 of 18
How do you work out the mass of a mole of any substance?
Work out the RFM and add grams at the end
11 of 18
How do we work out what percentage one element is of a compound?
1. Find the RFM 2. Divide the RAM of the substance you want to find by the RFM 3. Times by 100 + round if necessary
12 of 18
Find the percentage of carbon in CO2
1. RFM = 44 2. (RAM of carbon = 12 so..) 12/44 = 0.2727... 3. 0.273 x 100 = 27.3%
13 of 18
What is the empirical formula?
Simplest ratio of the atoms or ions in a compound. e.g CH3 or H2O
14 of 18
How do we work out the empirical percentage of a compound?
1. Divide the mass of each element in 100g of the compound by its RAM to give the ratio of atoms. 2. Convert this to the simplest whole number ratio. (divide by smallest)
15 of 18
Find the empirical formula of the compound that contains 70% iron and 30% oxygen
Iron = 70/56 = 1.25, Oxygen = 30/16 = 1.875 Simplest ratio = 1.25/1.25 = 1 and 1.875/1.25 = 1.5 so Empirical formula = 1:1.5 = 2:3 so Fe2O3
16 of 18
To work out the mass of reactant from the products what do we do?
1. Write the balanced equation and work out the RFM for the substances required. 2. Put it as a fraction with the unknown mass on top then write that equaling the fraction of the RFM's (unknown on top). Then rearange and work out the unknown.
17 of 18
Work out the mass of sodium chloride produced when 5.3g of aodium carbonate react with dilute HCl acid
Na2CO3 + 2HCl -> 2NaCl + H2O + CO2
18 of 18
Other cards in this set
Card 2
Front
what is the mass number?
Back
The total number of protons and neutrons in the nucleus of an atom.
Card 3
Front
Do atoms of the same elment have the same mass number or atomic number?
Comments
No comments have yet been made