Oxygen is the gas we breathe in. It can be separated from the air.
It boils at -183°C and freezes at -219°C.
How would you turn oxygen gas into solid oxygen?
Important Questions on States of Matter
Look at the glass tube below. Suppose it was warmed a little in an oven, before the experiment. Do you think that would change the result? If so, how?
The particles in hydrogen chloride gas are twice as heavy as those in ammonia gas.
• Cotton wool soaked in ammonia solution is put into one end of a long tube (at A below). It gives off ammonia gas.
• At the same time, cotton wool soaked in hydrochloric acid is put into the other end of the tube (at B). It gives off hydrogen chloride gas.
• The gases diffuse along the tube. White smoke forms where they meet:
