Class 9 Atoms and Molecules Important Questions
- When 3.0 g of carbon is burnt in 8.00 g oxygen, 11.00 g of carbon dioxide is produced. What mass of carbon dioxide will be formed when 6.00 g of carbon is burnt in 50.00 g of oxygen? Which law of chemical combination will govern your answer?
- What is the mass of:
- 0.2 mole of oxygen atoms?
- 0.5 mole of water molecules?
- 3.011 x 1023 number of N atoms?
- Which postulate of Dalton’s atomic theory is the result of the law of conservation of mass?
- Calculate the number of aluminium and oxygen ions present in 0.051 g of aluminium oxide ?
- Write the formula of :
- Calcium hydride
- Ammonium hydroxide
- Zinc sulphite
- sulphur dioxide
- calcium hydrogen carbonate
- A gold sample contains 90% of gold and rest of cpper. How many atoms of gold are present in one gram of this sample of gold.
- An element X of valency 3 combines with another element Y of valency 2. What will be the formula of the compound formed.
- Calculate the number of ions present in 5.85 g of sodium chloride.
- How many moles of calcium carbonate are present in 10 g of the substance?
- Calculate the mass of 3.011 x 1024 atoms of carbon.