Elements of life(EL) Flashcards
Group 2 element + oxygen
metal oxide and bright flame
Group 2 element + water
metal hydroxide and hydrogen
bubbles
Group 2 element + acid
salt and hydrogen
bubbling
Group 2 oxide + water
metal hydroxide
What happens to reactivity as you go down group 2?
Increases
Why does reactivity increase as you go down group 2?
1.)There is more shielding of outer electrons
2.)The attraction between the positive nucleus and outer electrons decrease
3.)The first and second ionisation energies increases
What happens to solubility as you go down group 2?
Increases
What is magnesium hydroxide,Mg(OH)2,used for?
Heartburn or Acid reflux
What is calcium hydroxide,Ca(OH)2 used for?
Agriculture,to neutralise acidic soil
Relative mass of an electron
1/2000
Define atomic number
The number of protons (or electrons) in an atom
Define mass number
The number of protons and neutrons in the nucleus of an atom
Define isotopes
Atoms with the same number of protons and electrons but different number of neutrons
Why do isotopes have slightly different physical properties?
Physical properties are often dependent more on the mass of the atom
Equation that links no. of moles,concentration and volume
No. of moles=concentration x volume (in dm3)
What is an ionic equation?
An ionic equation doesn’t include the spectator ions
What is an empirical formula?
The smallest whole number ratio of atoms in a compound
What is a molecular formula?
The actual number of atoms in a molecule
What is water of crystallisation?
Compounds with water molecules embedded into them
What happens when an ionic compund is dissolved in water?
The ions in its lattice seperate and are surrounded by a sphere of water molecules
Do hydrated or anhydrous compounds contain water of crystallisation
Hydrated
How do you calculate the formula of a hydrated compound from it anhydrous compound once water has been lost?
1.)Find the number of moles of water
2.)Find the number of moles of anhydrous salt
3.)Work out the ratio of moles of anhydrous salt to moles of water
What happens when a solid salt crystalises from an aqueous salt solution?
Water molecules become woven into the crystal lattice structure
How to calculate percentage yield?
percentage yield= actual yield/theoretical yield x 100
How to calculate the theoretical yield?
calcuate the moles of the reactant(s) then multiply by the Mr of the product
Why is percentage yield not 100%?
-Practical losses e.g during filtartion
-Icomplete reactions
-Side reactons
What are the four sub-shells?
s,p,d and f