Introducing chemical reactions - OCR Gateway test questions - OCR Gateway

1

What is the correct formula for carbon dioxide?

2

Water is produced when hydrogen reacts with oxygen. Which of these shows a balanced equation for this reaction?

3

What is the state symbol for a solid?

4

What is the empirical formula of C4H8O2?

5

3.0 g of carbon reacts with excess oxygen to form 11.0 g of carbon dioxide. What mass of oxygen reacted?

6

What is the relative formula mass of calcium carbonate, CaCO3? (Relative atomic masses: Ca = 40.1, C = 12.0, O = 16.0)

7

Iron(III) oxide contains Fe3+ ions and O2- ions. What is its formula?

8

Sodium nitrate contains Na+ ions and NO3- ions. What is its formula?

9

Which of these is a balanced ionic equation? - Higher

10

Which of these is a balanced half equation? - Higher