This question is about some gases present in air and the laboratory preparation of oxygen.
Which is the second most common gas in dry air? A. argon, B. carbon dioxide, C. nitrogen, D. oxygen.
Which gas makes up approximately 0.04% of dry air? A. argon, B. carbon dioxide, C. nitrogen, D. oxygen.
A ribbon of magnesium is heated and burned in air. State the formula and colour of the solid compound formed.
Oxygen gas can be prepared in the laboratory by adding a liquid dropwise from a tap funnel into a conical flask containing a solid catalyst, and collecting the gas over water. The liquid in the tap funnel is: A. dilute hydrochloric acid, B. dilute sulfuric acid, C. hydrogen peroxide solution, D. water.
The catalyst solid in the conical flask is: A. calcium carbonate, B. copper(II) oxide, C. manganese(IV) oxide, D. zinc.
Suggest another apparatus that can be used to collect the oxygen gas instead of collecting it over water.
Complete the equation for the catalytic decomposition of hydrogen peroxide by inserting the missing state symbols: 2H2O2(...)→2H2O(...)+O2(...)2\text{H}_2\text{O}_2(\text{...}) \rightarrow 2\text{H}_2\text{O}(\text{...}) + \text{O}_2(\text{...})2H2O2(...)→2H2O(...)+O2(...).
Describe the test used to identify oxygen gas and state the expected observation.
10 exam-style questions on Edexcel IGCSE Chemistry Gases in the atmosphere. Each one has a worked solution and a mark scheme showing where the marks go.