Ionic compounds Flashcards – AQA GCSE Combined Science: Trilogy (8464) — Chemistry — Higher

How are ions arranged in an ionic compound?

They form a giant three-dimensional lattice of positive and negative ions in a regular repeating pattern, not separate molecules.

What is ionic bonding in a giant ionic lattice?

Strong electrostatic attraction between oppositely charged ions, acting in all directions throughout the lattice.

Name a typical compound that forms a giant ionic lattice.

Sodium chloride.

What are three types of diagram used to represent ionic compounds?

Dot-and-cross diagrams, ball-and-stick models, and two- or three-dimensional lattice drawings.

What features identify an ionic structure in a diagram?

Positive and negative ions arranged in a repeating giant lattice, rather than as small discrete molecules.

What do dot-and-cross diagrams show about ionic compounds?

Electron transfer and ion charges.

What is a limitation of a dot-and-cross diagram of an ionic compound?

It does not realistically show the full giant lattice.

What is a limitation of a flat diagram of an ionic lattice?

It cannot fully show the three-dimensional lattice.

What can be misleading about a ball-and-stick model of an ionic structure?

It can suggest gaps or sticks that are not literally present in the real structure.

What does the empirical formula of an ionic compound represent?

The simplest whole-number ratio of ions in its giant lattice, not a single molecule.

How do you work out an ionic compound’s empirical formula from a model of its structure?

Find the relative numbers of positive and negative ions needed for electrical neutrality, then simplify to the lowest whole-number ratio.