Science Form 1, 2 & 3 Notes
Question 1:Name three impurities found in natural water resources. Answer:Dissolved mineral salts, solid suspended particles and microorganisms. Question 2:State water purification methods that can remove impurities in water. Answer:Filtration and distillation(Any other answers are accepted) Question 3:What are the major water pollution problems in coastal areas and in the sea? Answer:Oil spillage and disposal of … Read more
Activity 5.7:Aim: To study various water purification methods.Materials: Pond water, chlorine water, sterile nutrient agar, filter paper and cellophane tapeApparatus: Beaker, glass rod, filter funnel, measuring cylinder, Bunsen burner, wire gauze, Petri dish, distillation flask, Liebig condenser, retort stand with clamp, thermometer and one-hole rubber stopperInstruction1. Set up the apparatus as shown in Figure 5.21(a) … Read more
Question 1:Explain with examples the meaning of solute, solvent and solution. Answer:Sugar dissolves in water forming sugar water.Sugar is a solute, a substance that dissolves in a liquid.Water is a solvent, a liquid that dissolves a solute.Sugar water is a solution, a mixture of solute and solvent. Question 2:Explain one difference between solution and suspension. … Read more
Activity 5.6:Aim: To distinguish between a solution and a suspension.Materials: Copper(II) sulphate crystal, water, filter paper and chalk powderApparatus: Beaker, spatula, conical flask, filter funnel, measuring cylinder, glass rod, torchlight and white screenInstruction1. Measure and pour 100 ml of water into a beaker and add one spatula of copper(II) sulphate crystals.2. Stir the mixture until … Read more
Activity 5.5:Aim: To prepare dilute solution, concentrated solution and saturated solution.Materials: Distilled water and copper(II) sulphate crystalApparatus: Beaker, measuring cylinder, glass rod and spatula Instruction1. Fill three beakers labelled as P, Q and R with 50 ml of distilled water (Figure 5.13).2. Add two spatulas of copper(II) sulphate crystals into beaker P and stir until … Read more
Question 1:Ikram needs pure water to prepare a solution. His friend gave him a bottle of water. Suggest a way that he can use to determine whether the water is pure or not. Answer:• Boil the water – pure water boils at 100°C.• Determine the density of the water – density of pure water is … Read more
Experiment 5.1:Aim: To study the factors affecting the rate of evaporation of water.(A) Humidity:Problem statement: Does humidity affect the rate of evaporation of water?Hypothesis: The higher the humidity, the lower the rate of evaporation of water.Variables:(a) Constant variables: Surrounding temperature, volume of water, movement of air and exposed surface area of water(b) Manipulated variable: Humidity(c) … Read more
Activity 5.3:Aim: To observe the effects of impurities on the melting point and boiling point of water.Materials: Distilled water, ice cubes, two thick towels and table saltApparatus: Beaker, conical flasks, thermometer, spatula, Bunsen burner, tripod stand, wire gauze, two-hole rubber stopper, glass tube and stopwatch(A) The effect of table salt on the melting point of … Read more
Activity 5.2:Aim: To determine the composition of elements in a water molecule.Materials: Distilled water, dilute hydrochloric acid, wooden splinters and matchesApparatus: Electrolysis cell, switch, two measuring cylinders, dropper and crocodile clipsInstruction1. Label two measuring cylinders as K and L.2. Set up the apparatus as shown in Figure 5.4 by adding a few drops of dilute … Read more