Carbon
This allotrope of carbon is used in cutting tools because it is extremely hard.
Diamond
Name the particles that carry current in a molten ionic compound.
Ions
When the volume of a gas increases at constant temperature, what happens to its pressure?
It decreases- Boyles' law
What is the smallest particle of an element that retains its chemical properties?
Atom
When carbon burns in excess oxygen, this gas is formed.
Carbon (IV) oxide
Why does distilled water conduct electricity poorly?
It has very few ions
Why must temperature be converted to Kelvin when solving gas law calculations?
Because gas laws only work with absolute temperature (Kelvin scale)
What is the charge on a proton?
+1
Name the white solid formed when carbon (IV) oxide is passed through limewater.
Calcium carbonate
CO2 + Ca(OH)2 --> CaCO3 + H2O
Why does solid sodium chloride not conduct electricity?
Its ions are not free to move
State one condition that must be constant for Charles’ law to apply.
pressure
What type of bond is formed when electrons are shared between atoms?
Covalent bond
Explain why carbon (II) oxide can reduce copper (II) oxide when heated.
It removes oxygen from copper (II) oxide (acts as a reducing agent)
In electrolysis of lead (II) bromide (PbBr2), which gas is produced at the cathode?
Bromine gas, Br2
Which gas diffuses faster: hydrogen or oxygen? Explain why.
Hydrogen; it has a lower relative molecular mass.
Why are noble gases generally unreactive?
They have full outer electron shells. No valence electrons
During heating of limestone, a gas is released and a solid residue remains. Name the gas product that is released.
Carbon (IV) oxide
Explain why graphite is used as an electrode in electrolysis.
It conducts electricity, is non reactive and inexpensive
A gas occupies 100 cm³ at 273 K. What will happen to the volume if the temperature increases to 546 K at constant pressure?
It doubles to 200 cm³
V1/T1 = V2/T2
100/273 = V2/546
Balance this equation: Al + O₂ → Al₂O₃
4Al + 3O₂ → 2Al₂O₃