What do they mean when they say that concentrated nitric acid is 16 molar?

16 molar nitric acid is highly concentrated and corrosive in the extreme.

It means that in 1(one) litre of solution, there are 16 (sixteen) moles of nitric acid.

NB Under weaker solutions of nitric acid, the dissolution of copper has to be heated.

However, in 16M nitric acid , copper is readily dissolved without heating.

In the lab. take no more than 5 cm^(3) at a time, and handle it in the fume cupboard.

TREAT VERY CAREFULLY!!!!!

Have a solution of calcium hydroxide readily available in order to neutralise any spillages.