Properties of water equal to that of the hydrogen ion (), which gives a pH of 7 at 25 °C. Action of water on rock over long periods of time typically leads to weathering and water erosion, physical processes that convert solid rocks and minerals into soil and sediment, but under some conditions chemical reactions with water occur as well, resulting in metasomatism or mineral hydration, a type of chemical alteration of a rock which produces clay minerals. It also occurs when Portland cement hardens. Water ice can form clathrate compounds, known as clathrate hydrates, with a variety of small molecules that can
Water for injection Water for injection Water for injection is water of extra high quality without significant contamination. A sterile version is used for making solutions that will be given by injection. Before such use other substances generally must be added to make the solution more or less isotonic. It can be given by injection into a vein, muscle, or under the skin. A non-sterile version may be used in manufacturing with sterilization occurring later in the production process. If it is given by injection into a vein without making it more or less isotonic, breakdown of red blood cells may occur. This