Describe two ways in which the composition of sample A seawater differs from that of sample B.
Which positive ion in sample A has the lowest concentration?
Calculate the mass of sodium ions in $200\,\text{cm}^3$ of sample B, showing all working. [$1\,\text{dm}^3 = 1000\,\text{cm}^3$]
Describe a test for sodium ions. State the test and the result.
River water contains small clay particles. When these particles are examined under a microscope, they display a random, jerky movement even though the water is still. What is the name for this movement?
What does the symbol $\rightleftharpoons$ mean?
Describe how Universal Indicator paper could be used to find the pH of this solution.
Carbon dioxide is a greenhouse gas which leads to climate change. Explain how carbon dioxide contributes to climate change.
State the name of one additional greenhouse gas and give one source of this gas.