What is Alkali?
In [[chemistry]], an '''alkali''' is an aqueous (from water) solution with a [[pH]] value of more than [[7 (number)|seven]]. The word 'alkali' comes from the [[Arabic language|Arabic]] 'qali' meaning 'from the ashes' since ashes mixed with water used as cleaning products (such as soaps) are made of alkali materials. ==Example== *An alkali is where a [[Base (chemistry)|base]] is [[wikt:dissolve|dissolved]] in water. Often it is the [[salt]] of an [[Alkali metal]]. *An alkali is the opposite to an [[acid]] and can be neutralized (brought down to pH seven) by adding acid. == Characteristics == * It feels '''soapy'''. * It is '''[[corrosive]]''' (it can burn your skin away). * The higher the number is over seven on the pH scale the stronger the alkali is. * Highly soluble (can be dissolved) in water. * They have a bitter taste. * Turns red [[litmus paper]] blue. * Can conduct electricity due to the presence of mobile [[ion]]s. * Is it blue or purple on a [[universal indicator]]? == Strength == Like acids, alkalis can be weak or strong, depending on the nature and the concentration of the ionic salt composing it. The strength of an alkali can be found using universal indicator. Also like acids, the strength of an alkali is rated using the pH scale. For example, [[soap]] and [[toothpaste]] contain weak alkalis, while cleaning products often contain strong ones. [[File:Sodium hydroxide.jpg|250px|thumb|Sodium hydroxide]] == Examples of common alkalis == * [[Sodium hydroxide]], NaOH * [[Potassium hydroxide]], KOH * [[Calcium hydroxide]], Ca(OH)<sub>2</sub> * [[Aqueous ammonia]], NH<sub>3</sub> (aq) * [[Magnesium hydroxide]], Mg(OH)<sub>2</sub> == Uses of common alkalis == * [[Sodium hydroxide]] is used to make [[paper]], [[detergent]]s and [[soap]]. * [[Potassium hydroxide]] is used by farmers to make [[acid]]ic soil more alkaline so that plants will grow better in it, and is also used as the [[electrolyte]] in alkaline, Ni-Cd, and Ni-MH [[Battery|batteries]]. * [[Calcium hydroxide]] is used to neutralize acidic so