NATIONAL 5 CHEMISTRY, UNIT ONE PRATICE EXAM SOLUTION
QUESTIONS AND ANSWERS (University of Washington)
Electrolysis will only take place when a _____ _____ is passed into an electrolyte. (i.e. ionic
liquid or solution) - ANS IS Direct current. d.c.
(In a direct current there is a permanent positive or negative terminal - electrolysis will not occur
in an a.c. circuit)
In electrolysis, for a product to form on the terminal, it has to have the _____ charge as the
terminal - ANS IS opposite
Define; Electrolysis - ANS IS The break down of an ionic compound back into its elements using
electricity.
For electrolysis to take place, an ionic compound needs to be... - ANS IS freed. I.e. the ions are
free to move (such as in a liquid or solution).
Metal ions are always ____ charged. - ANS IS Positively
In electrolysis, the metal ions are always at the ______ terminal as they are _____ charged. -
ANS IS The metal ions are always at the *negative* terminal as they are *positively* charged.
In electrolysis, the non-metal ions are always at the ______ terminal as they are _____
charged. - ANS IS the non-metal ions are always at the *positive* terminal as they are
*negatively* charged.
A liquid which contains ions is called an... - ANS IS Electrolyte (Electrolytes conduct)
All ionic compounds form electrolytes when .... - ANS IS melted or in a solution
Metals conduct by carrying a flow of electrons. This is not how ionic solutions or liquids work.
They work by carrying a flow of - ANS IS ions.
The equations showing the ions being converted into atoms or molecules are called - ANS IS
ion electron half-equations.
,These are listed in the Electo-chemical series
In the electrochemical series, the equations for _____, _______, and ______ have to be
reversed. - ANS IS chlorine, bromine, and iodine
((If it helps these are all group7) Remember; When god decided to make these elements harder
to study, he was being a *B*romine *I*odine *Ch*lorine)
When a metal, or graphite, conducts the charged particles which move as the current are - ANS
IS electrons
When an ionic compound conducts the charged particles which move as the current are - ANS
IS ions
Atoms can bond by covalent or ionic bonding. Ionic bonding involved the ____ of electrons. -
ANS IS transfer
Atoms can bond by covalent or ionic bonding. Covalent bonding involved the ____ of electrons.
- ANS IS sharing
Page 20 of book 3 contains the Ions of elements. - ANS IS Look at them.
Two Li atoms are required to transfer an electron to a single oxygen atom to form an ionic
compound. Give the formula for the compound. - ANS IS (Li⁺)₂O²⁻
Three Al atoms are required to transfer electrons to two oxygen atoms for them all to obtain
stability. Give the formula if each Al atom has charge 3+ and O atom's 2- - ANS IS (Al³⁺)₂(O²⁻)₃
Covalent bonding occurs when ____-______ bond. - ANS IS Non-metals
Unpaired, outer electrons are referred as - ANS IS Valency (i.e. the Valency of Hydrogen is 1)
Describe a single bond between fluorine and how that would be written. - ANS IS Each has one
valency electron, and each of those fills the orbital to make them both stable.
, Each line (bond) on a covalent bonding diagram shows a _____ of _____ being shared. - ANS
IS Pair of electrons
Describe the double bond between oxygen and oxygen and how that would be written. - ANS IS
How would you write the diagram for a tetrahedral molecule? - ANS IS
Describe the shape of a tetrahedral molecule. - ANS IS
How would you write the diagram for a pyramidal molecule? - ANS IS
Describe the shape of a pyramidal molecule. - ANS IS
Describe the shape of a planar molecule. - ANS IS All atoms could sit on a sheet of paper
without any of them falling above or below the paper. *The molecule is flat.*
How would you write the diagram for a planar molecule? - ANS IS
How would you write the diagram for a linear molecule? - ANS IS
How are atoms held together in a covalent bond? - ANS IS The positive nuclei are attracted to
the negative shared pair of electrons. This holds them together.
Trick; To verify a ionic compound, take the number an ion and times that by it's charge. This will
be equal to the answer of the other ion. - ANS IS I.e. (Al³⁺)₂(O²⁻)₃
3×2=6
2×3=6
6=6
This is indeed a correct compound.
QUESTIONS AND ANSWERS (University of Washington)
Electrolysis will only take place when a _____ _____ is passed into an electrolyte. (i.e. ionic
liquid or solution) - ANS IS Direct current. d.c.
(In a direct current there is a permanent positive or negative terminal - electrolysis will not occur
in an a.c. circuit)
In electrolysis, for a product to form on the terminal, it has to have the _____ charge as the
terminal - ANS IS opposite
Define; Electrolysis - ANS IS The break down of an ionic compound back into its elements using
electricity.
For electrolysis to take place, an ionic compound needs to be... - ANS IS freed. I.e. the ions are
free to move (such as in a liquid or solution).
Metal ions are always ____ charged. - ANS IS Positively
In electrolysis, the metal ions are always at the ______ terminal as they are _____ charged. -
ANS IS The metal ions are always at the *negative* terminal as they are *positively* charged.
In electrolysis, the non-metal ions are always at the ______ terminal as they are _____
charged. - ANS IS the non-metal ions are always at the *positive* terminal as they are
*negatively* charged.
A liquid which contains ions is called an... - ANS IS Electrolyte (Electrolytes conduct)
All ionic compounds form electrolytes when .... - ANS IS melted or in a solution
Metals conduct by carrying a flow of electrons. This is not how ionic solutions or liquids work.
They work by carrying a flow of - ANS IS ions.
The equations showing the ions being converted into atoms or molecules are called - ANS IS
ion electron half-equations.
,These are listed in the Electo-chemical series
In the electrochemical series, the equations for _____, _______, and ______ have to be
reversed. - ANS IS chlorine, bromine, and iodine
((If it helps these are all group7) Remember; When god decided to make these elements harder
to study, he was being a *B*romine *I*odine *Ch*lorine)
When a metal, or graphite, conducts the charged particles which move as the current are - ANS
IS electrons
When an ionic compound conducts the charged particles which move as the current are - ANS
IS ions
Atoms can bond by covalent or ionic bonding. Ionic bonding involved the ____ of electrons. -
ANS IS transfer
Atoms can bond by covalent or ionic bonding. Covalent bonding involved the ____ of electrons.
- ANS IS sharing
Page 20 of book 3 contains the Ions of elements. - ANS IS Look at them.
Two Li atoms are required to transfer an electron to a single oxygen atom to form an ionic
compound. Give the formula for the compound. - ANS IS (Li⁺)₂O²⁻
Three Al atoms are required to transfer electrons to two oxygen atoms for them all to obtain
stability. Give the formula if each Al atom has charge 3+ and O atom's 2- - ANS IS (Al³⁺)₂(O²⁻)₃
Covalent bonding occurs when ____-______ bond. - ANS IS Non-metals
Unpaired, outer electrons are referred as - ANS IS Valency (i.e. the Valency of Hydrogen is 1)
Describe a single bond between fluorine and how that would be written. - ANS IS Each has one
valency electron, and each of those fills the orbital to make them both stable.
, Each line (bond) on a covalent bonding diagram shows a _____ of _____ being shared. - ANS
IS Pair of electrons
Describe the double bond between oxygen and oxygen and how that would be written. - ANS IS
How would you write the diagram for a tetrahedral molecule? - ANS IS
Describe the shape of a tetrahedral molecule. - ANS IS
How would you write the diagram for a pyramidal molecule? - ANS IS
Describe the shape of a pyramidal molecule. - ANS IS
Describe the shape of a planar molecule. - ANS IS All atoms could sit on a sheet of paper
without any of them falling above or below the paper. *The molecule is flat.*
How would you write the diagram for a planar molecule? - ANS IS
How would you write the diagram for a linear molecule? - ANS IS
How are atoms held together in a covalent bond? - ANS IS The positive nuclei are attracted to
the negative shared pair of electrons. This holds them together.
Trick; To verify a ionic compound, take the number an ion and times that by it's charge. This will
be equal to the answer of the other ion. - ANS IS I.e. (Al³⁺)₂(O²⁻)₃
3×2=6
2×3=6
6=6
This is indeed a correct compound.
