Question

\(\mathrm{CaCl}_{2}\)

Short answer

Calcium Chloride (CaCl2) is a compound consisting of one Calcium (Ca) atom and two Chlorine (Cl) atoms. It is an ionic compound formed by the transfer of electrons, where Calcium loses 2 electrons to form a Ca2+ ion and each Chlorine atom gains 1 electron to form Cl- ions, resulting in the formula CaCl2.

Step-by-step solution

Identify the elements

Calcium Chloride is a compound made up of two elements, Calcium (Ca) and Chlorine (Cl). In the given chemical formula, CaCl2, Ca represents Calcium and Cl represents Chlorine.

Determine the number of atoms

The subscript "2" after the Cl symbol shows that there are two atoms of Chlorine in the compound. There is no subscript after the symbol Ca, which means there is only one atom of Calcium. So, the compound has one Calcium atom and two Chlorine atoms.

Understand the ionic nature of the compound

Calcium Chloride is an ionic compound formed by the transfer of electrons between the Calcium atom and the Chlorine atoms. Calcium, an alkaline earth metal, will lose 2 electrons to form a Ca2+ ion, and each Chlorine atom will gain 1 electron to form Cl- ions. Therefore, the ionic formula for Calcium Chloride is Ca2+ Cl- Cl-, which is usually written as CaCl2.

Key concepts

Chemical Compound Composition

When we discuss the chemical compound composition, we refer to the types and quantities of atoms that form a compound. In the case of calcium chloride, its composition is relatively simple, consisting of two elements: calcium (Ca) and chlorine (Cl). Each element contributes its own unique properties to the final compound.

Calcium is a metallic element and plays the role of a cation in compounds, typically carrying a charge of +2 when it loses electrons. Chlorine, a non-metal, often functions as an anion with a charge of -1 when it gains an electron. In calcium chloride, one calcium atom (Ca²⁺) joins forces with two chlorine atoms (Cl^-), resulting in a neutral compound with a 1:2 ratio of calcium to chlorine. This ratio maintains electrical neutrality, as the charges from the calcium and chlorine ions balance each other out.

Ionic Compounds

Ionic compounds, such as calcium chloride, are formed through the electrostatic attraction between positively charged cations and negatively charged anions. These compounds are often created when a metal reacts with a non-metal. The metal atoms, like calcium in our example, lose electrons to become positively charged ions, while non-metal atoms, such as chlorine, gain electrons to become negatively charged ions.

In simpler terms, imagine a school dance where one group (the metals) is eager to give away their 'extra tickets' (electrons), and another group (non-metals) is more than happy to accept those tickets. The resulting 'partnerships' are stable pairs (ionic bonds) formed out of this exchange, leading to an overall neutral charge in the compound. Ionic compounds typically have high melting and boiling points, conduct electricity when dissolved in water, and form crystalline solids at room temperature.

Chemical Formulas and Subscripts

The chemical formula of a compound, like CaCl₂ for calcium chloride, is a compact way of communicating essential information about its composition. Such formulas use element symbols from the periodic table accompanied by numerical subscripts to indicate the number of atoms of each element present in a molecule of the compound.

These subscripts play a crucial role, as they show the proportions of the elements in a compound. For example, the '2' in CaCl₂ tells us that there are two chlorine atoms for every one calcium atom. If there is no subscript (as with the Ca in calcium chloride), it is understood to be '1'. Understanding these conventions is fundamental in chemistry, as they allow one to grasp the exact makeup of a compound at a glance, predict the ratios in which elements combine, and even determine the compound's stoichiometric calculations in chemical reactions.