Miracle Learning Centre Chemistry Tuition Question on Mole Concept. (O Level Chemistry Tuition/ IP Chemistry Tuition)

1. Steel pans sometimes blacken because of the sulfur coming from the proteins in eggs reacting with ions to form iron (II) sulfide. The equation for the reaction is shown below. Fe (s) + S (s)  FeS (s) What mass of iron (II) sulfide is formed from using the pans to fry a hundred eggs each containing 0.032 g of sulfur? A 0.88 g B 8.8 g C 88 g D 5.6 g

2. A solution contains 8.20 g/dm3 of the acid H3ZO3. 25.0 cm3 of this solution reacted with an equal volume of 0.100 mol/dm3 NaOH. The equation for the reaction was NaOH + H3ZO3  NaH2ZO3 + H2O What is element Z? A nitrogen B phosphorus C silicon D sulfur

3. An aqueous solution of a salt was placed in a test tube and sodium hydroxide was added from a burette. The height of the precipitate formed in the tube was measured from various volumes of alkali added and a graph was shown below: height of precipitate volume of alkali added Which of the following salts would show this behaviour? I aluminium sulfate II zinc sulfate III ammonium sulfate A I only B I and II only C II and III only D I, III and III

Miracle Learning Centre Answer to Chemistry Tuition Question on Mole Concept . (O Level Chemistry Tuition/ IP Chemistry Tuition) 1.B 2.B 3.B Learn from our Chemistry Tuition Questions and Answers. Miracle Learning Centre Call 6463 8756 or sms 8128 8342/9839 9908. (Specialist in Science and Maths) for Primary, Secondary and JC levels. Miracle Learning Centre specialises in Chemistry tuition, Physics tuition, Maths tuition and Science tuition Classes.

Miracle Learning Centre Chemistry Tuition Question on Extraction and Properties of Metals. (O Level Chemistry Tuition/ IP Chemistry Tuition)

1 Iron is extracted from its ore in a blast furnace. The raw materials in this process are iron ore, coke, limestone and air.

(a) Write an overall equation for the blast furnace process. _____________________________________________________________ (b) Describe the role of the following raw materials in this process. (i) limestone ________________________________________________ (ii) coke ________________________________________________ (c) Steel, an alloy of iron, is a very important structural material. What is a major disadvantage of using steel as a structural material? _____________________________________________________________ Miracle Learning Centre Answer to Chemistry Tuition Question on Extraction and Properties of Metals . (O Level Chemistry Tuition/ IP Chemistry Tuition) 1.a.i.Fe2O3 + 3CO  2Fe + 3CO2 1.b.i.limestone: decomposes to form lime (CaO) which reacts with the acidic impurities to form slag. b.ii.coke: reacts with oxygen to produce carbon monoxide which acts as the reducing agent. c.Iron in steel rusts relatively quickly. Learn from our Chemistry Tuition Questions and Answers. Miracle Learning Centre Call 6463 8756 or sms 8128 8342/9839 9908. (Specialist in Science and Maths) for Primary, Secondary and JC levels. Miracle Learning Centre specialises in Chemistry tuition, Physics tuition, Maths tuition and Science tuition Classes.