Silicon tetrachloride exists as a covalent molecule. What is the valency of silicon in this molecule? Give reasons for your answer.
SiCl4. Cl is -1, there are four of them to make -4 total; therefore, Si must be +4 to leave a 0 charge on the molecule.
To determine the valency of silicon in silicon tetrachloride (SiCl4), we need to understand the concept of valency and the bonding in the molecule.
Valency refers to the number of electrons an atom needs to gain, lose, or share to achieve a stable electron configuration. Silicon belongs to Group 14 in the periodic table, also known as the carbon family. Group 14 elements have four valence electrons, which means they need to gain or lose four electrons to achieve stability.
In the case of silicon tetrachloride (SiCl4), silicon forms covalent bonds with four chlorine atoms. Covalent bonds involve the sharing of electrons between atoms. Each chlorine atom contributes one electron to the bond, while silicon contributes four electrons.
To determine the valency of silicon, we can consider the number of electrons it shares in the covalent bonds. Since silicon shares four electrons with the four chlorine atoms, it achieves a stable electron configuration by completing its octet (eight valence electrons) in SiCl4. Hence, the valency of silicon in silicon tetrachloride is four.
In summary, the valency of silicon in silicon tetrachloride (SiCl4) is four, as it shares four electrons with the four chlorine atoms to achieve a stable electron configuration.