South Axholme School
ATOMIC STRUCTURE
Q1. (a) State the relative charge and relative mass of a proton, of a neutron and of an
electron.
In terms of particles, explain the relationship between two isotopes of the same element.
Explain why these isotopes have identical chemical properties.
(7)
(b) Define the term relative atomic mass. An element exists as a mixture of three isotopes.
Explain, in detail, how the relative atomic mass of this element can be calculated from
data obtained from the mass spectrum of the element.
(7)
(Total 14 marks)
Page 1
, South Axholme School
PERIODICITY
Q2. (a) Explain why certain elements in the Periodic Table are classified as p-block elements.
Illustrate your answer with an example of a p-block element and give its electronic
configuration.
(3)
(b) Explain the meaning of the term periodicity as applied to the properties of rows of
elements in the Periodic Table. Describe and explain the trends in atomic radius, in
electronegativity and in conductivity for the elements sodium to argon.
(13)
(Total 16 marks)
Page 2
, South Axholme School
AMOUNT OF SUBSTANCE
Q3.(a) Calcium phosphate reacts with aqueous nitric acid to produce phosphoric acid and calcium
nitrate as shown in the equation.
Ca3(PO4)2 + 6HNO3 2H3PO4 + 3Ca(NO3)2
(i) A 7.26 g sample of calcium phosphate reacted completely when added to an excess
of aqueous nitric acid to form 38.0 cm3 of solution.
Calculate the concentration, in mol dm–3, of phosphoric acid in this solution.
Give your answer to 3 significant figures.
(5)
(ii) Calculate the percentage atom economy for the formation of calcium nitrate in this
reaction.
Give your answer to 1 decimal place.
(2)
(b) Write an equation to show the reaction between calcium hydroxide and phosphoric acid to
produce calcium phosphate and water.
(1)
(c) Calcium dihydrogenphosphate can be represented by the formula Ca(H2PO4)x where x is
an integer.
A 9.76 g sample of calcium dihydrogenphosphate contains 0.17 g of hydrogen, 2.59 g of
phosphorus and 5.33 g of oxygen.
Calculate the empirical formula and hence the value of x.
Show your working.
(4)
(Total 12 marks)
Page 3
, South Axholme School
AMOUNT OF SUBSTANCE
Q4. The chloride of an element Z reacts with water according to the following equation.
ZCl4(l) + 2H2O(l) → ZO2(s) + 4HCl(aq)
A 1.304 g sample of ZCl4 was added to water. The solid ZO2 was removed by filtration and the
resulting solution was made up to 250 cm3 in a volumetric flask. A 25.0 cm3 portion of this
solution was titrated against a 0.112 mol dm–3 solution of sodium hydroxide, of which 21.7 cm3
were required to reach the end point.
Use this information to calculate the number of moles of HCl produced and hence the number
of moles of ZCl4 present in the sample. Calculate the relative molecular mass, Mr, of ZCl4.
From your answer deduce the relative atomic mass, Ar, of element Z and hence its identity.
(Total 9 marks)
Page 4
ATOMIC STRUCTURE
Q1. (a) State the relative charge and relative mass of a proton, of a neutron and of an
electron.
In terms of particles, explain the relationship between two isotopes of the same element.
Explain why these isotopes have identical chemical properties.
(7)
(b) Define the term relative atomic mass. An element exists as a mixture of three isotopes.
Explain, in detail, how the relative atomic mass of this element can be calculated from
data obtained from the mass spectrum of the element.
(7)
(Total 14 marks)
Page 1
, South Axholme School
PERIODICITY
Q2. (a) Explain why certain elements in the Periodic Table are classified as p-block elements.
Illustrate your answer with an example of a p-block element and give its electronic
configuration.
(3)
(b) Explain the meaning of the term periodicity as applied to the properties of rows of
elements in the Periodic Table. Describe and explain the trends in atomic radius, in
electronegativity and in conductivity for the elements sodium to argon.
(13)
(Total 16 marks)
Page 2
, South Axholme School
AMOUNT OF SUBSTANCE
Q3.(a) Calcium phosphate reacts with aqueous nitric acid to produce phosphoric acid and calcium
nitrate as shown in the equation.
Ca3(PO4)2 + 6HNO3 2H3PO4 + 3Ca(NO3)2
(i) A 7.26 g sample of calcium phosphate reacted completely when added to an excess
of aqueous nitric acid to form 38.0 cm3 of solution.
Calculate the concentration, in mol dm–3, of phosphoric acid in this solution.
Give your answer to 3 significant figures.
(5)
(ii) Calculate the percentage atom economy for the formation of calcium nitrate in this
reaction.
Give your answer to 1 decimal place.
(2)
(b) Write an equation to show the reaction between calcium hydroxide and phosphoric acid to
produce calcium phosphate and water.
(1)
(c) Calcium dihydrogenphosphate can be represented by the formula Ca(H2PO4)x where x is
an integer.
A 9.76 g sample of calcium dihydrogenphosphate contains 0.17 g of hydrogen, 2.59 g of
phosphorus and 5.33 g of oxygen.
Calculate the empirical formula and hence the value of x.
Show your working.
(4)
(Total 12 marks)
Page 3
, South Axholme School
AMOUNT OF SUBSTANCE
Q4. The chloride of an element Z reacts with water according to the following equation.
ZCl4(l) + 2H2O(l) → ZO2(s) + 4HCl(aq)
A 1.304 g sample of ZCl4 was added to water. The solid ZO2 was removed by filtration and the
resulting solution was made up to 250 cm3 in a volumetric flask. A 25.0 cm3 portion of this
solution was titrated against a 0.112 mol dm–3 solution of sodium hydroxide, of which 21.7 cm3
were required to reach the end point.
Use this information to calculate the number of moles of HCl produced and hence the number
of moles of ZCl4 present in the sample. Calculate the relative molecular mass, Mr, of ZCl4.
From your answer deduce the relative atomic mass, Ar, of element Z and hence its identity.
(Total 9 marks)
Page 4
