5 Formulae, Equations and Amounts of Substance Flashcards
Define “relative atomic mass”
The average mass of 1 atom of an element compared to 1/12 of the mass of 1 atom of Carbon-12
Define “mole”
The amount of substance that has the same number of elementary particles as there are atoms in 12g of Carbon-12
Define “empirical formula”
The simplest whole number ratio between atoms
Define “molecular formula”
The actual number of atoms present in the compound
What is the “standard condition” in Chemistry?
- 25 degrees Celsius (298 K)
- 1 atm (100 000 Pa)
Ideal gas equation?
pV = nRT
Define “atomic mass”
The number of protons and neutrons in the nucleus of an atom
Define “atomic number”
The number of protons in the nucleus
Define “atom economy”
Measure of the amount of starting materials that become useful products
Define “percentage yield”
Way of comparing amount of product made to amount expected
Reasons for not getting expected mass in a chemical reaction?
- loss when filtering
- loss when transferring liquids
- loss when evaporating
- not all reactant was made into product
Why is high atom economy wanted?
- less unwanted products made
- important for sustainable development by using fewer natural resources and create less waste
What compounds are always soluble?
All salts of:
- Group IA
- ammonium
- nitrates
- chlorates
- acetates
Solubility of salts of halides?
Soluble except:
- silver (I)
- copper (I)
- lead (II)
- mercury (I)
Solubility of salts of sulfates?
Soluble except:
- barium sulfate
- lead (II) sulphate
- strontium sulfate
