Which of the following correctly explains why an acid shows acidic behaviour only in aqueous solution?
Hydrogen ions (H+) are produced only when the acid dissolves in water.
Acidic character is defined by the release of hydrogen ions (H+), which in water exist as hydronium ions (H3O+).
A pure acid such as HCl gas or glacial ethanoic acid contains covalent molecules; without water there is no medium to solvate and separate the ions, so the acid does not ionise and shows no acidic behaviour (dry HCl gas does not turn blue litmus red).
When the acid is dissolved in water, water molecules pull the H+ away from the acid molecule and stabilise it as H3O+, which is what produces the sour taste, litmus change and reaction with metals or bases.
Hence, hydrogen ions are produced only when the acid dissolves in water.
Metals of medium reactivity are generally found in the form of which compounds?
Which of the following is the purest form of iron?
Which of the following is the carbon allotrope having a tetrahedral structure?
A student is comparing samples of sulphur, carbon (Diamond), and bromine. Which property is least likely to be observed in all three?
The study of metals and their properties belongs to which branch of chemistry?
Which material would be the best choice for electrical transmission lines?
Which process is commonly used to extract iron, a metal in the middle of the activity series, from its ore?
Why are metals like sodium and potassium not found in the free state in nature?
Imagine a region with abundant ancient plant remains, frequent earthquakes, and thick rock layers. Which fossil fuel is most likely to be found there and why?
Which sequence best describes the steps for obtaining a pure metal from its ore?