States of Matter

You will be able to

• Deduce the state of a substance at a given temperature from its melting and boiling points, with its state symbol.
• Describe the arrangement and motion of the particles in a solid, a liquid and a gas.
• Explain why the temperature stays constant during melting and boiling on a heating curve, and read melting and boiling points from a curve.

You will be able to

• Describe diffusion as the random movement of particles from a higher to a lower concentration.
• Explain why the ammonium chloride ring forms nearer the hydrogen chloride end: lighter molecules diffuse faster.
• Predict the effect of relative molecular mass and of temperature on the rate of diffusion.