Combined Science Revision Question 1 Outline how industrial gases are manufactured from air. Solution 1 Air is cooled to -78°C. Water and carbon dioxide are removed as solids. The remaining air is further cooled by a process of rapid compression and expansion until it reaches a temperature of -200°C. At this temperature all gases are …
Mixed Revision Questions and Answers (Page 1) Question 1 Use the table below to answer the questions that follow: Substance pH A 1 B 5 C 7 D 9 E 14 a) Which substance is a weak alkali? b) Which substance could be water? c) Which substance is a weak acid? d) Which substance could …
Acids, Bases and Salts Questions and Answers (Page 1) Question 1 Dry hydrogen chloride gas does not turn blue litmus paper red. It dissolves in water and toluene. Some properties of the two solutions are listed below: HCl in toluene HCl in water Nuetral to litmus Turns litmus paper red Does not conduct electricity Conducts …
Stoichiometry Questions and Answers(Page 2) Question 1 Sodium sulphate has the following composition by mass: sodium 32.4%, sulphur 22.5% and oxygen 45.1%. What is its empirical formula? Solution 1 Sodium Sulphur Oxygen Mass 32.4 22.5 45.1 Moles 32.4/23 22.5/32 45.1/16 = 1.41 = 0.7 = 2.82 Molar Ratio 1.41/0.7 0.7/0.7 2.82/0.7 = 2 = 1 …
Stoichiometry Questions and Answers (Page 1) Use the values of Ar which follow to answer the questions below. [H = 1; C = 12; N = 14; O = 16; Ne = 20; Na = 23; Mg = 24; S = 32; K = 39; Fe = 56; Cu = 63.5; Zn = 65. ] …