(i) Name the acid that renders aluminium passive. Why?
(ii) What are hygroscopic substances differ from deliquescent substances.

Name the acid that render aluminium passive. Why ?

In what way hygroscopic substances differ from deliquescent dubstances .

Why specific heat is different for different substances? Explain (AS_1)

Sita is a owner of confectionary. She got an order from one of her customers to prepare 150 loaves of bread for a birthday party. On her making process of bread, though there is a time constrain, she prepared the dough and kept it aside undisturbed for few hours. Later she made the required number of breads and delivered to customer on time. A day after the party, customer appreciated Sita for the soft and good quality of bread that she supplied to party. (a) Why Sita kept aside the dough undisturbed? (b) Name the living organism involved in the process. (c) What are the products of the process? (d) How this process enhances the quality of food?

We often find small packets of silica gel in food packs leather and electronic goods . What are hygroscopic substances ?