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Metals react with acids to form salts and hydrogen gas. Liberation of hydrogen gas when zinc reacts with hydrochloric acid. + () + [2] [3] However less reactive metals can not displace the hydrogen from acids. [3] (They may react with oxidizing acids though.)
Water-reactive substances [1] are those that spontaneously undergo a chemical reaction with water, often noted as generating flammable gas. [2] Some are highly reducing in nature. [ 3 ] Notable examples include alkali metals , lithium through caesium , and alkaline earth metals , magnesium through barium .
Zinc oxide is generally recognized by the FDA as safe and effective [187] and is considered a very photo-stable. [188] Zinc oxide is one of the most common active ingredients formulated into a sunscreen to mitigate sunburn. [75] Applied thinly to a baby's diaper area with each diaper change, it can protect against diaper rash. [75]
Zinc is a strong reducing agent with a standard redox potential of −0.76 V. Pure zinc tarnishes rapidly in air, rapidly forming a passive layer. The composition of this layer can be complex, but one constituent is probably basic zinc carbonate, Zn 5 (OH) 6 CO 3. [8] The reaction of zinc with water is slowed by this passive layer.
Metal oxides which react with both acids as well as bases to produce salts and water are known as amphoteric oxides. Many metals (such as zinc, tin, lead, aluminium, and beryllium) form amphoteric oxides or hydroxides. Aluminium oxide (Al 2 O 3) is an example of an amphoteric oxide. Amphoterism depends on the oxidation states of the oxide.
A metal ion in aqueous solution or aqua ion is a cation, dissolved in water, of chemical formula [M(H 2 O) n] z+.The solvation number, n, determined by a variety of experimental methods is 4 for Li + and Be 2+ and 6 for most elements in periods 3 and 4 of the periodic table.
The following chart shows the solubility of various ionic compounds in water at 1 atm pressure and room temperature (approx. 25 °C, 298.15 K). "Soluble" means the ionic compound doesn't precipitate, while "slightly soluble" and "insoluble" mean that a solid will precipitate; "slightly soluble" compounds like calcium sulfate may require heat to precipitate.
Zinc forms Zintl phases such as LiZn, NaZn 13 and BaZn 13. [59] Highly purified zinc, at room temperature, is ductile. [60] It reacts with moist air to form a thin layer of carbonate that prevents further corrosion. [61] Cadmium is a soft, ductile metal (MH 2.0) that undergoes substantial deformation, under load, at room temperature. [62]