Reactivity Series of Metals 1. Three experiments to investigate the reactivities of metals are shown below. Results of placing metal in a solution of Metal salt of chromium salt of manganese salt of iron Chromium No reaction No reaction Iron is displaced Chromium is Manganese No reaction Iron is displaced displaced Iron No reaction No reaction No reaction What is the order of reactivity of the metals? Most reactive Least reactive A Chromium Manganese Iron B Iron Chromium Manganese C Manganese Chromium Iron D Manganese Iron Chromium ( ) 2. The table shows the results of adding weighed pieces of zinc metal in salt solutions of metal P, Q and R. Salt solution of metal Initial mass of zinc / g Mass of zinc after 15 minutes / g P 5.0 0.0 Q 5.0 5.0 R 5.0 3.5 Which of the following shows the correct arrangement of metals in decreasing reactivity? A P, R, zinc, Q C Q, zinc, P, R B R, P, zinc, Q D Q, zinc, R, P ( ) 3. Which oxide can be reduced to its metal by carbon? A Calcium oxide C Magnesium oxide B Sodium oxide D Iron(II) oxide ( ) 4. Carbon can be used to reduce to its metal. A aluminium oxide C sodium oxide B lead(II) oxide D calcium oxide ( ) 5. Which statement about both lead and copper is correct? A They react with acid and hydrogen is released. B Their oxides can be reduced to metals using carbon. C Their sulfates dissolve in water. D All of their compounds are coloured. ( ) 1 LTD Chemistry.indb 1 8/12/2016 9:57:25 AM 6. The metals iron, lead and zinc can be obtained by reduction of their oxides using coke. Which of the following shows the ease of reduction of the metal oxides? Decreasing ease of reduction A Iron, lead, zinc B Iron, zinc, lead C Zinc, lead, iron D Lead, iron, zinc ( ) 7. Equal masses of copper(II) oxide were heated separately in oxygen and hydrogen. What changes (if any) would you expect in the masses of the copper(II) oxide? Mass after heating in oxygen Mass after heating in hydrogen A Unchanged Decreased B Decreased Decreased C Decreased Unchanged D Unchanged Unchanged ( ) 8. Sacrificial protection is one of the methods to prevent corrosion. Which of the following metals is not suitable to be made into sacrificial metal to prevent iron from rusting? A Aluminium B Copper C Zinc D Magnesium ( ) 9. Why does aluminium seem unreactive? A It has 3 valence electrons. B It has a coat of aluminium oxide. C It is low in the reactivity series. D It has a low activation energy. ( ) 10. The reactivity of aluminium is compared to zinc by observing their reaction with water and dilute acid. It appears that aluminium has a slower rate of reaction as compared to zinc for both instances. This is because . A aluminium is less reactive than zinc B aluminium is protected by a layer of oxide C zinc has a greater affinity to liquids than aluminium D zinc self catalyses the reactions ( ) Adapted: Upper Secondary Chemistry Tutorial © Singapore Asia Publishers Pte Ltd. All rights reserved. Reproducible for home/classroom use only. 2 STRICTLY NOT FOR SALE. Look for other useful resources: www.sapgrp.com LTD Chemistry.indb 2 8/12/2016 9:57:26 AM Answers to Reactivity Series of Metals 1. C Chromium can displace iron from its salt solution. Hence, chromium is more reactive than iron (eliminate option D). Manganese can displace chromium and iron from their salt solutions. Hence, manganese must be most reactive metal (eliminate options A and B). 2. D When zinc has reacted, the mass of zinc will decrease. Zinc has displaced P from its salt solution. Hence, zinc must be more reactive than P (eliminate options A and B). Zinc cannot displace Q from its salt solution. Hence, zinc must be less reactive than Q. Zinc has displaced R from its salt solution to a lesser extent when compared with P. Hence, R must be more reactive than P (eliminate option C). 3. D The metal must be lower than carbon in the reactivity series. 4. B This question is similar to Question 3. 5. B Copper is below hydrogen in the reactivity series. Hence, copper cannot react with acids (eliminate option A). Lead(II) sulfate is insoluble in water (eliminate option C). Lead(II) oxide and lead(II) chloride is white (eliminate option D). Both lead and copper are below carbon in the reactivity series. 6. D Reactive metals form stable oxides. Hence, the metals must be increasing in reactivity from left to right. 7. A Copper(II) oxide does not react with oxygen. Hence, the mass is unchanged (eliminate options B and C). Hydrogen is higher than copper in the reactivity series and will reduce copper oxide to form copper and water. 8. B Copper is below iron in the reactivity series and will not ionise in place of iron. 9. B Aluminium is reactive and will form a protective layer of aluminium oxide on its surface. 10. B Adapted: Upper Secondary Chemistry Tutorial © Singapore Asia Publishers Pte Ltd. All rights reserved. Reproducible for home/classroom use only. A1 STRICTLY NOT FOR SALE. Look for other useful resources: www.sapgrp.com LTD Chemistry.indb 1 8/12/2016 9:57:26 AM.