What is the chemical symbol for sodium?
Na
How many different elements are there in a molecule of carbon dioxide?
2
Where does an endothermic reaction take its heat from?
The surroundings
In paper chromatography, what instrument should you use to draw the start line?
A pencil
What do we call atoms with the same number of protons but different numbers of neutrons?
Isotopes
What type of bonding is present in calcium oxide?
Ionic
Complete the word equation: Lead oxide + carbon ->
-> lead + carbon dioxide
What do we call the energy required for a reaction to begin?
Activation energy
Which gas produces a squeaky pop when placed near a lit splint?
Hydrogen
What method of separation would we use to extract pure water from salt water?
Distillation
What element is graphene made from?
Carbon
Aluminium, iron, silver.
Bond energies are usually given in kJ per what?
Mole
In paper chromatography, why must you never draw the start line in pen?
The ink will dissolve.
In chromatography there are two phases. One is the mobile phase. What is the other?
The stationary phase.
In solution.
What does the acronym OILRIG stand for?
Oxidation if loss, reduction is gain.
Water decomposes to form which two elements?
Hydrogen and oxygen
What name is given to mixtures that are designed as useful products?
Formulations
Octane has a higher boiling point than pentane. Why?
It has larger molecules.
A nitrogen molecule consists of two nitrogen atoms covalently bonded. How may pairs of electrons do they share?
3
What will appear at the positive electrode during the electrolysis of sodium sulfate solution?
Oxygen
Balance the equation: C5H12 + O2 ---> CO2 + H2O
C5H12 + 8O2 ---> 5CO2 + 6H2O
How do you work out the Rf value in chromatography?
Distance moved by ink/distance moved by solvent