Is Matter Around Us Pure — Science STD 9 — Question

What type of clothes should we wear in summer? Why?

Potassium chlorate decomposes, on heating, to form potassium chloride and oxygen. When 24.5g of potassium chlorate is decomposed completely, then 14.9g of potassium chloride is formed. Calculate the mass of oxygen formed. Which law of chemical combination have you used in solving this problem?

You are provided with a fine white coloured powder which is either sugar or salt. How would you identify it without testing?

Potassium chlorate decomposes, on heating, to form potassium chloride and oxygen. When 24.5g of potassium chlorate is decomposed completely, then 14.9g of potassium chloride is formed. Calculate the mass of oxygen formed. Which law of chemical combination have you used in solving this problem?

How is scrap iron separated from a heap of waste materials in factories?

How are given mass, molar mass and number of moles related to each other?

How many moles of oxygen atoms are present in one mole of the following compounds?

1. Al₂O₃
2. CO₂
3. Cl₂O₇
4. H₂SO₄
5. Al₂(SO₄)₃

Why is heat energy needed to melt a solid? What is this heat energy called?

Identify the total number of inert gases, their names and symbols from this cross word puzzle.

What is the value of the latent heat of fusion of ice?