3rd May Mock - Key Facts Flashcards
(22 cards)
What is the formula for a chlorine molecule?
Cl2
What is the formula for an ammonia molecule?
NH3
What is the formula for a hydrogen molecule?
H2
What is the formula for an oxygen molecule?
O2
What is the formula for an ammonium ion?
NH4 +
What is the formula for a nitrate ion?
NO3 -
What is the formula for a sulphate ion?
SO4 2-
What is the formula for a hydroxide ion?
OH -
What is the formula for a carbonate ion?
CO3 2-
Ar (Relative Atomic Mass) =
(∑(relative isotopic mass * isotopic percentage abundance) / sum of abundances [100%]
Where is the divide between metals and non-metals on the periodic table?
Boron is the most left non-metal, from there the divide is like stairs downwards.
What are positively charged ions called?
Cations
What are negatively charged ions called?
Anions
What are the advantages and disadvantages of 2D representations of atoms?
Advantages:
• Show what atoms something contains
• Show how the atoms are connected
Disadvantages:
• Don’t show the shape of the substance
• Don’t represent the relative sizes of the atoms
What are the advantages and disadvantages of dot and cross diagrams?
Advantages:
• Show how compounds/molecules are formed
• Show how atoms are connected
Disadvantages:
• Don’t show the relative size of the atoms/ions
• Don’t show how the atoms/ions are arranged
What are the advantages and disadvantages of ball and stick models?
Advantages:
• Good at visualising structures
• Show the shape of the lattice or molecule
Disadvantages:
• There are big gaps where, in reality, the electron clouds interact
• Don’t show the correct scales of atoms/ions
What is Mr?
Relative formula mass - the relative atomics masses of all the atoms in a formula combined
concentration (g dm^-3) =
mass of solute (g) / volume of solution (dm^3 (litres))
(no. of) moles =
mass/Mr
no. of particles =
moles * Avogrado’s constant
What is Avogadro’s constant?
6.02 * 10^23
Rf value =
distance travelled by solute / distance travelled by solvent
