What do you observe when dilute sulphuric acid is added to granulated zinc

This is a quick and easy experiment that can be done individually or in pairs. Equipment Apparatus • Eye protection • Test tubes x3 • Test tube rack • Measuring cylinder, 10 cm 3 • Dropping pipette Chemicals • Granulated zinc, a few pieces • Copper turnings or powder, a few pieces / half a spatula • Dilute sulfuric acid, 1 M (IRRITANT), 15 cm 3 • Copper(II) sulfate(VI) solution, 0.5 M, a few cm 3 Health, safety and technical notes • • Wear eye protection. • Dilute sulfuric acid, H 2SO 4(aq)(IRRITANT) – see CLEAPSS Hazcard HC098a, CLEAPSS Recipe BookRB098 andCLEAPSS L195 ‘Safer chemicals, safer reactions’. • Copper(II) sulfate(VI) solution, CuSO 4(aq) – see CLEAPSSHazcardHC027c andCLEAPSSRecipe Book RB031. Procedure • Put a few pieces of granulated zinc into each of the three test tubes. Try to have approximately the same amount in each test tube. • Add 5 cm 3of dilute sulfuric acid to test tube 1. Note the rate of production of gas bubbles. • Add a few copper turnings to test tube 2. Make sure they are in contact with the zinc. Add 5 cm 3of dilute sulfuric acid and note the rate of production of gas bubbles. • Add 5 cm 3of dilute sulfuric acid to test tube 3. Then add about 1 cm 3of the copper sulfate solution using a dropping pipette. Note the rate of production of gas bubbles. Note what happens to the colour of the copper sulfate solution. Note what happens to the surface of the pieces of zinc. Teaching notes If the granulated zinc pieces are shiny then the reaction in t...

The experiment is done first on a smaller scale using test tubes (lesson 1 below), with no attempt to recover the salts formed. This establishes that hydrogen production is a characteristic property of the reaction of metals and acids. It can then be done on a larger scale (lesson 2 below), and the salts formed can be recovered by crystallisation. Lesson 1 is a series of test tube experiments in which each working group establishes as a common feature that hydrogen is given off as metals react with an acid – if the metal reacts at all. This should take around 40 minutes, and most classes should be able to do this version. Each working group needs a small selection of metals and acids to test. The range of metals and acids tested can be extended to a teacher demonstration in the concluding part of this lesson. Lesson 2, in which the salt formed is recovered by crystallisation, takes longer, and the class needs to be reliable enough in behaviour and manipulative skills to cope with the hazards involved in heating acidic solutions in beakers on tripods. The time taken for the reaction depends on the particle size of the metal used. Using small granules helps to reduce the time taken. Equipment Apparatus Lesson 1 • Eye protection • Test tubes, 100 mm x 16 mm or similar, x8 • Test tube rack • Corks or bungs to fit test tubes loosely, x2 • Bunsen burner • Wood splint Lesson 2 • Conical flask, 100 cm 3 • Beaker, 100 cm 3 • Measuring cylinder, 100 cm 3 • Glass stirring rod • Spatu...

Plan a lesson on this topic Try this practical as part of a complete Equipment Apparatus • Eye protection • Test tubes, x3 • Test tube rack • Test tube holder • Dropping pipettes, x2 Chemicals • Copper(II) sulfate solution, 1.0 M (HARMFUL), about 3 cm 3(see note 3 below) • Ammonia solution, 1.0 M, about 10 cm 3 • Dilute sulfuric acid, 1.0 M (IRRITANT), about 10 cm 3 Health, safety and technical notes • • Wear eye protection throughout. • Copper(II) sulfate solution, CuSO 4(aq),(HARMFUL) – see CLEAPSS HazcardHC027c and CLEAPSS Recipe Book RB031. The copper(II) sulfate solution is most conveniently supplied in a bottle fitted with teat pipette. • Ammonia solution, NH 3(aq) – see CLEAPSSHazcardHC006 and CLEAPSS Recipe Book RB006. • Dilute sulfuric acid, H 2SO 4(aq)(IRRITANT) – see CLEAPSSHazcardHC098a and CLEAPSSRecipe Book RB098. Procedure • While wearing eye protection, put 10 drops of copper(II) sulfate solution into each of two test tubes. • Add ammonia solution drop-by-drop to the first test tube. Shake the tube gently from side to side after adding each drop. What happens as you add a few drops of the solution? • Add more drops of ammonia solution. What happens? Continue until you have a clear blue solution. • Divide the solution from step 3into two test tubes. Add dilute sulfuric acid drop-by-drop to one of the solutions from step 3. Shake the tube gently from side to side after adding each drop. Do you get back to where you started – compare the three test tubes? • Ca...

What do you observe when (a) dilute sulphuric acid is added to granulated zinc? (b) a few pieces of iron are dropped in a blue solution of copper sulphate? (c) silver nitrate is added to a solution of sodium chloride? (d) ferrous sulphate solution is added to an aqueous solution of sodium hydroxide. (e) solid lead nitrate is heated? (f) when dilute sulphuric acid is added to barium chloride solution ? (a) When Zinc reacts with the dilute sulphuric acid, hydrogen gas is evolved with an effervescence. Zn + dil . H 2SO 4→ Zn SO 4+ H 2. (b) When a few pieces of iron are dropped into a blue colored copper sulphate solution, the blue color of the solution fades and eventually turns to green. (c) When a solution of silver nitrate is added to a solution of sodium chloride, white insoluble ppt. of silver chloride is formed. AgNO 3(aq) + NaCl (aq) → AgCl (ppt) + NaNO 3(aq) (d) When ferrous sulphate solution is added to sodium hydroxide solution, a dirty green ppt. of ferrous hydroxide is formed. FeSO 4(aq) + 2NaOH (aq) → Fe(OH) 2↓ + Na 2SO 4(aq) (e) When solid lead nitrate is heated, it decomposes to produce light yellow solid lead monoxide, reddish brown nitrogen dioxide gas and colorless oxygen gas. (f) When few drops of dilute sulphuric acid are added to barium chloride solution, a white precipitate of barium sulphate is formed.