8.3 Preparation of Salts

Transcription

1 For more awesome GSE and level resources, visit us at 8. Preparation of Salts Question Paper Level IGSE Subject hemistry (060) Exam oard ambridge International Examinations (IE) Topic cids ases and Salts Sub-Topic 8. Preparation of Salts ooklet Question Paper Time llowed: 5 minutes Score: / Percentage: /00 Grade oundaries: * E U >85% 75% 60% 45% 5% 5% <5%

2 For more awesome GSE and level resources, visit us at method used to make copper(ii) sulfate crystals is shown Place dilute sulfuric acid in a beaker. Warm the acid. dd copper(ii) oxide until it is in excess. Filter the mixture. Evaporate the filtrate until crystals start to form. Leave the filtrate to cool. What are the purposes of step and step 4? step step 4 to ensure all of the acid has reacted to ensure all of the acid has reacted to speed up the reaction to speed up the reaction to obtain solid copper(ii) sulfate to remove excess copper(ii) oxide to obtain solid copper(ii) sulfate to remove excess copper(ii) oxide What is the correct sequence of steps for the preparation of a pure sample of copper(ii) sulfate crystals from copper(ii) oxide and sulfuric acid? dissolving crystallisation evaporation filtration dissolving evaporation filtration crystallisation dissolving filtration crystallisation evaporation dissolving filtration evaporation crystallisation Salts can be made by adding different substances to dilute hydrochloric acid. For which substance could any excess not be removed by filtration? copper(ii) oxide magnesium sodium hydroxide zinc hydroxide

3 For more awesome GSE and level resources, visit us at 4 Four stages in the preparation of a salt from an acid and a solid metal oxide are listed. 4 dd excess solid. Evaporate half the solution and leave to cool. Filter to remove unwanted solid. Heat the acid. In which order should the stages be carried out? salt is produced in each of the following reactions. P Q R S magnesium + dilute hydrochloric acid zinc oxide + dilute sulfuric acid sodium hydroxide + dilute hydrochloric acid copper carbonate + dilute sulfuric acid Which statements about the products of the reactions are correct? flammable gas is produced in reaction P. Water is formed in all reactions. ll the salts formed are soluble in water., and and only and only and only 6 Zinc sulfate is a soluble salt and can be prepared by reacting excess zinc carbonate with dilute sulfuric acid. Which piece of equipment would not be required in the preparation of zinc sulfate crystals? beaker condenser evaporating dish filter funnel

4 For more awesome GSE and level resources, visit us at 7 Four steps to prepare a salt from an excess of a solid base and an acid are listed. 4 crystallisation evaporation filtration neutralisation In which order are the steps carried out? Which method is used to make the salt copper sulfate? dilute acid + alkali dilute acid + carbonate dilute acid + metal dilute acid + non-metal oxide 9 Which two processes are involved in the preparation of magnesium sulfate from dilute sulfuric acid and an excess of magnesium oxide? neutralisation and filtration neutralisation and oxidation thermal decomposition and filtration thermal decomposition and oxidation

5 For more awesome GSE and level resources, visit us at 0 How many different salts could be made from a supply of dilute sulfuric acid, dilute hydrochloric acid, copper, magnesium oxide and zinc carbonate? Which salt preparation uses a burette and a pipette? calcium nitrate from calcium carbonate and nitric acid copper(ii) sulfate from copper(ii) hydroxide and sulfuric acid potassium chloride from potassium hydroxide and hydrochloric acid zinc chloride from zinc and hydrochloric acid Which acid reacts with ammonia to produce the salt ammonium sulfate? hydrochloric nitric phosphoric sulfuric

6 For more awesome GSE and level resources, visit us at opper carbonate reacts with dilute sulfuric acid to make copper sulfate. uo (s) + H SO 4 (aq) uso 4 (aq) + O (g) + H O(l) Which row gives the correct order of steps for making copper sulfate crystals? step step step step 4 add excess acid to filter evaporate filtrate to leave to cool the copper carbonate point of crystallisation add excess acid to the copper carbonate filter evaporate to dryness leave to cool add excess copper carbonate to the acid evaporate to point of crystallisation leave to cool filter add excess copper carbonate to the acid filter evaporate filtrate to point of crystallisation leave to cool 4 Which acid reacts with ammonia to produce the salt ammonium sulfate? hydrochloric nitric phosphoric sulfuric 5 nhydrous copper(ii) sulfate can be made by heating hydrated copper(ii) sulfate. uso 4.5H O uso 4 + 5H O What can be added to anhydrous copper(ii) sulfate to turn it into hydrated copper(ii) sulfate? concentrated sulfuric acid sodium hydroxide powder sulfur dioxide water

7 For more awesome GSE and level resources, visit us at 6 compound is a salt if it can neutralise an acid. contains more than one element. dissolves in water. is formed when an acid reacts with a base. 7 Salts X and Y are separately dissolved in water. Samples of the solutions obtained are separately tested with dilute hydrochloric acid and with aqueous sodium hydroxide. In two of the tests, a gaseous product is formed. No precipitate is formed in any of the tests. What are salts X and Y? X Y gno aso 4 aso 4 Na O Na O NH 4 l NH 4 l gno 8 liquid turns white anhydrous copper sulfate blue and has a boiling point of 0. Which could be the identity of the liquid? alcohol petrol salt solution pure water

8 For more awesome GSE and level resources, visit us at 9 salt is made by adding an excess of an insoluble metal oxide to an acid. How can the excess metal oxide be removed? chromatography crystallisation distillation filtration 0 n excess of copper(ii) oxide is added to dilute sulfuric acid to make crystals of hydrated copper(ii) sulfate. The processes listed may be used to obtain crystals of hydrated copper(ii) sulfate. 4 concentrate the resulting solution filter heat the crystals wash the crystals Which processes are needed and in which order?,,,,

9 For more awesome GSE and level resources, visit us at Salts can be prepared by reacting a dilute acid with a metal; with a base; with a carbonate. Which methods could be used to prepare copper(ii) chloride? and only and only and only,