Within ocean floor sediments, large amounts of carbon dioxide are trapped within ice as 'carbon dioxide hydrate', CO2⋅xH2O\text{CO}_2 \cdot x\text{H}_2\text{O}CO2⋅xH2O. Carbon dioxide makes up about 29.5%29.5\%29.5% of the mass of 'carbon dioxide hydrate'.
Scientists are concerned that ocean warming or pressure changes will melt the hydrate clathrates, releasing large quantities of carbon dioxide into the oceans and atmosphere.
The H-O-H\text{H-O-H}H-O-H bond angle in ice is about 109∘109^\circ109∘ but about 104.5∘104.5^\circ104.5∘ in gaseous H2O\text{H}_2\text{O}H2O. Explain why there is this difference.
Why are scientists concerned about the release of carbon dioxide into the atmosphere?
Determine the formula of 'carbon dioxide hydrate', CO2⋅xH2O\text{CO}_2 \cdot x\text{H}_2\text{O}CO2⋅xH2O. In the formula, show the value of xxx to two decimal places.
Calculate the volume of carbon dioxide, in dm3\text{dm}^3dm3, that would be released from the melting of each 1.50 kg1.50\text{ kg}1.50 kg of 'carbon dioxide hydrate' at 100 kPa100\text{ kPa}100 kPa and 20∘C20^\circ\text{C}20∘C. Give your answer to three significant figures.
Suggest why some environmental industries are interested in the formation or presence of 'carbon dioxide hydrate' in deep ocean sediments.
199 exam-style questions on OCR A A Level Chemistry Atoms and reactions, covering Atomic structure and isotopes, Compounds, formulae and equations, Amount of substance, Acids, and Redox. Each one has a worked solution and a mark scheme showing where the marks go.