An very urgent question

When the water is being evaporated from the hydrated copper (II) sulphate crystals, the water vapours condenses at once when they are cooled down. After this step, the cooled water vapours will become drops of water(水滴). If test tube is not held in a slanting position, the drops of water accumulated on the wall of the test tube due to condensation of water vapours, will go back to the heating up hydrated copper (II) sulphate crystals due to the gravity. The efficiency of removing water from hydrated copper (II) sulphate crystals will decrease. And more time is required to completely turn hydrated copper (II) sulphate crystals to dehydrated copper (II) sulphate crystals. Hence, holding the test tube in a slanting position is required.(支test tube的底部在高位置,而test tube個咀在低的位置.)
I hope you will find them helpful.