Foundations In Chemistry Flashcards
What is the charge of a proton
1+
What is the charge of an electron
1-
Which particle has the same mass as a proton
Neutron
Which two particles make up most of an atoms mass
Protons and neutrons
Which letter is used to represent the atomic number of an atom
Z
What does the atomic number tell us
The number of protons
Which letter represents the mass number
A
How to calculate the number of neutrons
Mass number- atomic number
Define isotope
Same protons different neutrons
What are ions
Charged particles formed when an atom loses/gains electrons
Define relative atomic mass
The weighted mean mass of an atom of an element compared with one twelfth of the mass of an atom of carbon-12
Define relative isotopic mass
The mass of an atom of an isotope compared with one twelfth of the mass of an atom of carbon-12
What two assumptions are made when calculating mass number
Contribution of electron is ignored and the mass of both proton and neutron is taken as 1.0u
How to calculate relative molecular mass and relative formula mass
Add relative atomic masses of each atom making up the molecule or the formula
3 uses of mass spectroscopy
Identify unknown compounds
Find relative abundance of each isotope
Determine structural information
How does a mass spectrometer work
Sample made into positive ions
Pass through Apparatus and separated according to mass to charge ratio
A computer analyses the data and produces mass spectrum
Do metals usually gain or lose electrons
Lose electrons
What are molecular ions
Covalently bonded atoms that lose or gain electrons
Charge of an ammonium ion
+1
Charge of a hydroxide ion
-1
Charge of a hydroxide ion
-1
Charge of a nitrate ion
-1
Carbonate ion
-2
Sulfate ion
-2
Empirical formula
Simplest whole number ratio
Calculate empirical formula
Divide amount by molar mass
Divide by smallest number
If decimal decide by suitable number to make whole
Symbol for amount of substance
n
Unit to measure amount of substance
Mole
What does avogadro constant represent
Number of atoms per mole of carbon-12 isotope
Calculate mass of 1 mole of an element
Relative atomic mass in grams
Mole equation
Moles=mass/ molar mass
Avogadros law
Under the same temperature and pressure one mole of any gas would occupy the same volume
How much volume does a gas occupy at room temperature and pressure
24dm^3
Define molar gas volume
Volume per mole of gas molecules
Why do different gas particles occupy the same volume
Gas particles are very spread out so individuals differences have no effect
Moles when gas volume is given
Moles=volume(dm^3)/24
Moles=volume(cm^3)/24000
Ideal gas equation
Pressure(Pa)×volume(m^3) =moles×gas constant(8.314)×temperature(k)
0°c = how many kelvin
273
What does concentration of a solution mean
Amount of solute dissolved in 1dm^3 of solvent
Moles when given concentration and volume
Moles=conc×vol
What is a standard solution?
A solution of a known concentration
Steps to prepare a standard solution
Weigh solution
Dissolve solute using solvent
Pour into volumetric flask
Rinse beaker using solution and add it to flask
Add solvent until it reaches graduation line
Mix thoroughly
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What does percentage yield mean
Efficiency reactants are converted into products