Thermal decomposition of nitrates

Take a look at the following video which shows the effect of heat on sodium nitrate. This is typical of the group 1 nitrates.

Video - the effect of heat on sodium nitrate.

Watch the following video in which there is no commentary. A glowing splint is used to test for oxygen in each case. Make notes of the changes you observe for each nitrate which is heated. This is good practice for the observation work required in some practical assessments.

Video - the effect of heat on the group 2 metal nitrates

What do your observations suggest about the trend in thermal stability of these nitrates as we go down the group? Try to explain the trend that you discover - it must have something to do with the different metal ions involved. Write down equations for each of the reactions seen. How did the stability of the group 1 nitrate compare with those of group 2? Check your observations and answers using this theory link.

Poisonous nitrogen dioxide gas is made in these group 2 reactions so they must be done in a fume cupboard