Planet Earth and Nature of matter
Sulfurs melting point is 115 degrees and its boiling point is 444 degrees. What state is sulfur at room temperature?
solid
An atom of Flourine is represented by 199F. How many electrons does this atom have?
9
acid + base -> ? + ?
salt + water
What 4 factors affect the rate of a chemical reaction?
temperature, pressure, concentration (if liquid), surface area (if solid), catalyst
Name the simplest 5 carbon alkane.
pentane
What gas is the most abundant in the air?
Nitrogen (78%)
What is the chemical formula for magnesium bromide
MgBr2
acid + metal -> ? + ?
acid + metal carbonate -> ? + ?
salt + hydrogen
salt + water + carbon dioxide
What is the name of the type of reaction that releases heat?
Exothermic
What destinguishes:
alkanes
alkenes
alcohols
alkane- fully saturated
alkenes- contain at least one double bond
alcohols- contain an -OH (hydroxyl) group
Catalytic converters in cars help protect us from releasing dangerous pollutants into the atmosphere. They convert carbon monoxide and nitrogen dioxide into....?
carbon dioxide and nitrogen
Balance the following equation:
_H2SO4 + _NaOH -> _Na2SO4 + _H2O
H2SO4 + 2NaOH -> Na2SO4 + 2H2O
How many moles of hydrochloric acid is in 2 dm3 hydrochloric acid solution with a concentration of 0.3 mol/dm3?
0.6 moles
moles=concentration×volume
What is the catalyst for the Haber process (ammonia manufacture)?
iron
What is the chemical test for alkenes? And what is a positive result?
bromine test. orange/ brown changes to colourless.
Which method would you use to seperate ethanol from water?
fractional distillation
What is created from the electrolysis of molten lead(II) bromide? Which ion is reduced and which is oxidized?
Pb2+ is reduced to lead and and Br- is oxidized to bromine gas
Calculate the relative formula mass of ethanol.
46 g/mol
Why does aluminium not corrode like iron?
Aluminium unlike iron, forms a thin, transparent oxide layer on its surface when exposed to air. This oxide layer acts as a protective barrier, preventing further oxidation of the metal underneath. In contrast, the oxide layer that forms on iron is porous and allows water and air to reach the underlying metal, leading to further oxidation and rusting.
name two chemical groups that could be present in monomers that can make polymers through condensation reactions?
hydroxyl (-OH)
carboxyl (-COOH)
amine (-NH2)
Explain the difference between the terms: atom, ion, molecule
Atom: The smallest unit of matter that retains the properties of an element.
Ion: An atom or molecule with a net electric charge due to loss or gain of electrons.
Molecule: A group of atoms covalently bonded together.
Correctly identify the type of bonding (ionic, simple covalent, or macromolecular covalent) in each of the following substances:
Sodium bromide
Calcium Carbonate
Graphite
Water
Silicon dioxide
Sodium bromide (ionic)
Calcium Carbonate (ionic/ covalent)
Graphite (macromolecular covalent)
Water (simple covalent)
Silicon dioxide (macromolecular covalent)
What mass of magnesium oxide can be made from 6g of magnesium?
10g of MgO
Give three distinctive properties of transition metals (properties that are the same as other metals- eg. conductivity- do not count)
form coloured compounds
form ions with more than one possible charge
can be used as catalysts
some are magnetic
What is the common chemical test for carbon dioxide? What is a positive result?
bubbling it through limewater. positive for carbon dioxide if the limewater turns milky.