This page provides practice exercises for drawing dot and cross diagrams for covalent bonds and coordinate bonds. It aims to help students visualize and understand molecular structures and bond formation in various compounds.

The worksheet is divided into two main sections:

1. Covalent Bonding Diagrams Students are asked to draw dot-and-cross diagrams for covalently bonded molecules. This section includes examples such as:

   a) Carbonyl chloride (COCl₂) b) Carbon sulfide (CS₂)

   Example: For carbonyl chloride (COCl₂), the diagram shows the central carbon atom bonded to one oxygen atom and two chlorine atoms, with electrons represented by dots and crosses.

2. Coordinate Bond Formation This section focuses on illustrating the formation of coordinate (or dative) bonds. Two examples are provided:

   i) The reaction between boron trifluoride (BF₃) and ammonia (NH₃) to form F₃BNH₃

   Highlight: This example demonstrates how the lone pair of electrons from the nitrogen atom in ammonia is shared with the boron atom in boron trifluoride, forming a coordinate bond.

   ii) The formation of the phosphonium ion (PH₄⁺) from phosphine (PH₃) and a hydrogen ion (H⁺)

   Vocabulary: A coordinate bond (also known as a dative bond) is a type of covalent bond where both electrons in the shared pair come from the same atom.

The worksheet provides space for students to draw their answers, encouraging hands-on practice in representing these molecular structures and bonding types.

Definition: Dot and cross diagrams are visual representations of molecular structures that show the arrangement of valence electrons around atoms using dots and crosses to distinguish electrons from different atoms.

This practice sheet is an excellent resource for students studying covalent bonding and coordinate bond formation, providing a practical approach to understanding these fundamental concepts in chemistry.