The Periodic Table Banker

1. (a) Which property is typical of transition elements?A low densityB they form coloured compoundsC low melting pointsD they react vigorously with cold water [1]

1. (a) Compare the melting points and densities of iron and sodium. [2]
2. (b) State one way in which iron or its compounds are used as a catalyst. [1]
3. (c) State the colour of a solution of a typical copper(II) compound, such as copper(II) sulfate. [1]

1. (a) Give two properties of copper that make it suitable for electrical wiring in homes. [2]
2. (b) Copper is a transition element. State one physical property, other than conductivity, that copper has in common with other transition elements. [1]
3. (c) Copper roofs on old buildings turn green. Suggest what this shows about copper compounds. [1]

1. (a) Iron forms two chlorides, FeCl₂ and FeCl₃. Give the oxidation number of iron in each. [2]
2. (b) Name FeCl₃ using an oxidation number. [1]
3. (c) Describe a test with aqueous sodium hydroxide that distinguishes solutions of the two chlorides. Give both results. [2]
4. (d) State the property of transition elements shown by iron forming both chlorides. [1]

1. (a) Name the catalyst used in the Contact process and give the oxidation number of vanadium in it. [2]
2. (b) Explain why transition elements and their compounds are useful in industry as catalysts. [2]

The table gives some properties of four metals, J, K, L and M.J: melting point 98 °C; density 0.97 g/cm³; compounds whiteK: melting point 1538 °C; density 7.87 g/cm³; compounds green or red-brownL: melting point 650 °C; density 1.74 g/cm³; compounds whiteM: melting point 1085 °C; density 8.96 g/cm³; compounds blue or green

1. (a) Which two elements are most likely to be transition elements? Give two pieces of evidence from the table. [3]
2. (b) Element J reacts rapidly with cold water. Suggest which group J is in. [1]

1. (a) Give the oxidation number of manganese in MnO₂ and in KMnO₄. [2]
2. (b) Give the oxidation number of chromium in Cr₂O₃ and in K₂Cr₂O₇. [2]
3. (c) Use your answers to state a property that manganese and chromium share with other transition elements. [1]
4. (d) Name manganese(IV) oxide's role when it is added to hydrogen peroxide. [1]

Chromium is extracted by heating chromium(III) oxide with aluminium powder.Cr₂O₃ + 2Al → Al₂O₃ + 2Cr [Ar: O, 16; Cr, 52]

1. (a) Give the oxidation number of chromium in Cr₂O₃ and in Cr. [1]
2. (b) Explain whether chromium(III) oxide is oxidised or reduced in this reaction. [1]
3. (c) Calculate the mass of chromium formed from 76 g of chromium(III) oxide. [2]
4. (d) Chromium is used to plate steel taps. Suggest two reasons. [2]

1. (a) Which halogen is a red-brown liquid at room temperature?A fluorineB chlorineC bromineD iodine [1]

1. (a) Describe how the colour and state of the halogens change from chlorine to iodine. [2]
2. (b) Chlorine is added to the water supply in cities such as Lahore. State why. [1]
3. (c) State how the reactivity of the halogens changes down the group. [1]

1. (a) Which mixture of aqueous solutions reacts to form a new halogen?A iodine + potassium chlorideB bromine + potassium chlorideC chlorine + potassium bromideD iodine + potassium bromide [1]

1. (a) Describe what is seen when chlorine water is added to colourless aqueous potassium bromide. [1]
2. (b) Write the ionic equation for the reaction. [2]
3. (c) Explain why there is no reaction when bromine water is added to aqueous potassium chloride. [1]
4. (d) State which species is oxidised in (b). [1]

Astatine, At, is below iodine in Group VII.

1. (a) Predict the state and colour of astatine at room temperature. [2]
2. (b) Predict whether astatine will react with aqueous potassium iodide. Explain. [2]
3. (c) Write the formula of the compound formed between sodium and astatine. [1]

A student adds aqueous solutions of halogens to aqueous solutions of potassium halides and records whether the colour changes.chlorine + potassium bromide: ?bromine + potassium iodide: ?iodine + potassium bromide: ?chlorine + potassium iodide: brown colour

1. (a) Give the result for each blank: (i) chlorine with potassium bromide; (ii) bromine with potassium iodide; (iii) iodine with potassium bromide. [3]
2. (b) Use the results to put chlorine, bromine and iodine in order of reactivity, most reactive first. [1]
3. (c) Write the ionic equation for reaction (ii). [2]

Cl₂ + 2KI → 2KCl + I₂ [Ar: Cl, 35.5; I, 127]

1. (a) Calculate the mass of iodine formed when 0.710 g of chlorine reacts with excess aqueous potassium iodide. [3]
2. (b) Fluorine is at the top of Group VII. Predict how its reactivity compares with chlorine and suggest why it is not used in school experiments. [2]

1. (a) An element is in Group III and Period 3 of the Periodic Table. What is its electronic configuration?A 2,3B 2,8,3C 2,3,8D 2,8,8,3 [1]

1. (a) An element has the electronic configuration 2,8,6. State its group and period, and name it. [3]
2. (b) State how the group number of an element is related to its electronic configuration. [1]
3. (c) State how the period number is related to its electronic configuration. [1]

1. (a) How does the nature of the oxides of the elements change across Period 3 from sodium to chlorine?A acidic to basicB basic to acidicC basic to neutralD they are all basic [1]

1. (a) Classify sodium, silicon and chlorine as metal, metalloid-like (semi-metal) or non-metal, and describe the trend in metallic character across a period. [3]
2. (b) State how metallic character changes down Group IV, from carbon to lead. [1]

Melting points of the Period 3 elements (°C): Na 98, Mg 650, Al 660, Si 1410, P 44, S 115, Cl −101, Ar −189.

1. (a) Name the element with the highest melting point and explain it in terms of structure. [3]
2. (b) Explain why chlorine has a low melting point. [2]
3. (c) Which elements in the table are solids at 100 °C? [1]

1. (a) Strontium is in Group II, Period 5. Predict (i) the formula of strontium chloride, (ii) whether strontium oxide is acidic or basic, (iii) how its reactivity compares with that of magnesium. [3]
2. (b) Selenium is in Group VI, below sulfur. Predict the formula of its hydride and the type of oxide it forms. [2]

1. (a) Element Q forms an ion Q²⁻ that has 18 electrons. Identify Q and give its group. [2]
2. (b) Element R forms an ion R³⁺ that has 10 electrons. Identify R. [1]
3. (c) Write the formula of the compound formed between R and Q. [1]
4. (d) Explain, in terms of their positions, why R and Q form an ionic compound. [2]

1. (a) Why is argon used to fill filament light bulbs?A It is very unreactive.B It conducts electricity.C It has a very low density.D It glows bright red. [1]

1. (a) Give the electronic configurations of neon and argon. [2]
2. (b) Explain why the noble gases are unreactive. [1]
3. (c) State why noble gases exist as single atoms. [1]

Boiling points of noble gases (°C): helium −269, neon −246, argon −186, krypton −153, xenon −108.

1. (a) Describe the trend in boiling point down the group. [1]
2. (b) Predict the boiling point of radon, the next element in the group. [1]
3. (c) Helium is used in weather balloons launched from Karachi. Give two properties that make it suitable. [2]

1. (a) Explain why helium is used instead of hydrogen in airships even though hydrogen is less dense. [2]
2. (b) Argon is used as a shield gas when welding steel. Suggest why. [1]
3. (c) Compare the reactivity of potassium (Group I) with that of argon in terms of their electron arrangements. [3]

1. (a) Potassium reacts with water. What are the products?A potassium oxide and hydrogenB potassium hydroxide and hydrogenC potassium hydroxide and oxygenD potassium oxide and oxygen [1]

1. (a) Describe three things seen when a small piece of sodium is added to a trough of water. [3]
2. (b) A few drops of universal indicator were in the water. State the final colour and explain. [1]
3. (c) Write the balanced equation for the reaction. [2]

Melting points of Group I metals (°C): lithium 181, sodium 98, potassium 63.

1. (a) Describe the trend in melting point down Group I. [1]
2. (b) Predict the melting point of rubidium, the next element after potassium. [1]
3. (c) State how the reactivity with water changes down the group. [1]
4. (d) Explain why Group I metals are stored under oil. [1]

0.46 g of sodium reacts completely with water.2Na + 2H₂O → 2NaOH + H₂ [Ar: Na, 23; molar volume 24 dm³ at r.t.p.]

1. (a) Calculate the volume of hydrogen formed at r.t.p. [2]
2. (b) The solution is made up to 250 cm³. Calculate the concentration of sodium hydroxide in mol/dm³. [2]
3. (c) Predict one observation that would be different if the same experiment were done with caesium. Explain. [2]