Capitolo Chimica

Trasformazioni della materia, energia e ambiente

Chemistry in English


IPCC (Intergovernmental Panel on Climate Change
Summary for Policymakers

Approved at the 11th Session of Working Group III of the IPCC, Abu Dhabi, United Arab Emirates, 5-8 May 2011.


Read the text and answer the questions

Box SPM.1 | Renewable energy sources and technologies considered in this report

[...] Ocean energy
derives from the potential, kinetic, thermal and chemical energy of seawater, which can be transformed to provide electricity, thermal energy, or potable water. A wide range of technologies are possible, such as barrages for tidal range, submarine turbines for tidal and ocean currents, heat exchangers for ocean thermal energy conversion, and a variety of devices to harness the energy of waves and salinity gradients. Ocean technologies, with the exception of tidal barrages, are at the demonstration and pilot project phases and many require additional R&D*. Some of the technologies have variable energy output profiles with differing levels of predictability (e.g., wave, tidal range and current), while others may be capable of near-constant or even controllable operation (e.g., ocean thermal and salinity gradient).
Wind energy
harnesses the kinetic energy of moving air. The primary application of relevance to climate change mitigation is to produce electricity from large wind turbines located on land (onshore) or in sea- or freshwater (offshore). Onshore wind energy technologies are already being manufactured and deployed on a large scale. Offshore wind energy technologies have greater potential for continued technical advancement. Wind electricity is both variable and, to some
degree, unpredictable, but experience and detailed studies from many regions have shown that the integration of wind energy generally poses no insurmountable technical barriers. [...]
* R&D research and development
  1. How can the kinetic energy of wind be exploited?
  2. What are the types of energy mentioned in the excerpt under the heading “Ocean Energy”?
  3. What sets in motion turbines submerged in the sea?
  4. Which of the technologies cited in the report has already been implemented on a large scale?

Test your knowledge

  1. Which of these is an example of an exothermic chemical process?
    1. evaporation of water
    2. ice melting
    3. photosynthesis of glucose
    4. combustion of gasoline
  2. The superscript ° in the term \(\Delta H_{f}^{^{\circ}}\) means:
    1. the reaction is carried out at zero degrees Celsius
    2. the enthalpy of the reaction is zero
    3. the reaction is carried out at standard conditions.
    4. the reaction is carried out at zero pressure.
comprehension cap. 7.
summing-up cap. 7.

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