Chemical Reactions and Equations PDF

Figure 1.8 (b) Iron nails and copper sulphate solutions compared before and after the experiment Why does the iron nail become brownish in colour and the blue colour of copper sulphate solution fades? The following chemical reaction takes place in this Activity– Fe(s) + CuSO4(aq) →...

Figure 1.8 (b) Iron nails and copper sulphate solutions compared before and after the experiment Why does the iron nail become brownish in colour and the blue colour of copper sulphate solution fades? The following chemical reaction takes place in this Activity– Fe(s) + CuSO4(aq) → FeSO4(aq) + Cu(s) (1.24) (Copper sulphate) (Iron sulphate) In this reaction, iron has displaced or removed another element, copper, from copper sulphate solution. This reaction is known as displacement reaction. Other examples of displacement reactions are Zn(s) + CuSO4(aq) → ZnSO4(aq) + Cu(s) (1.25) (Copper sulphate) (Zinc sulphate) Pb(s) + CuCl2(aq) → PbCl2(aq) + Cu(s) (1.26) (Copper chloride) (Lead chloride) Zinc and lead are more reactive elements than copper. They displace copper from its compounds. 1.2.4 Double Displacement Reaction Activity 1.10 n Take about 3 mL of sodium sulphate solution in a test tube. n In another test tube, take about 3 mL of barium chloride solution. n Mix the two solutions (Fig. 1.9). n What do you observe? You will observe that a white substance, which is insoluble in water, is formed. This insoluble substance formed is known as a precipitate. Any reaction that Figure 1.9 produces a precipitate can be called a precipitation reaction. Formation of barium sulphate and sodium Na2SO4(aq) + BaCl2(aq) → BaSO4(s) + 2NaCl(aq) (1.27) chloride (Sodium (Barium (Barium (Sodium sulphate) chloride) sulphate) chloride) Chemical Reactions and Equations 11 2024-25