Class – IX
Subject –Chemistry
(Atoms and molecules)
1. An element Z forms a formula ZO3. Find the valency of Z and O in this formula.
2. write the formulae of the following ions
a. sulfide ion
b. sulphite ion
c. carbonate ion
d. hydrogencabonate ion
3. Give an example of conservation of mass theory.
4. State whether this statement is true or false.
The symbol of cobalt is CO.
5. Write the full name of IUPAC.
(Section B) 5 x2 =10
6. Define Mole with example.
7. What is the mass of .5 mole of water (H2O).
8. Calculate the molecular mass of HNO3. (Atomic mass of H= 1u, N = 14 u and O = 16u.)
9. Calculate the number of iron atom in the piece of iron weighing 2.8 g ( atomic mass of iron is 56u)
10. Which postulate of Dalton’s Atomic theory can explain the law of conservation of mass?
11. Write the all three law of chemical combination.
(Section C) 2x5 =10
12. Sodium carbonate reacts with ethanoic acid to form sodium ethanoate, carbon oxide and water. In an experiment 5.3 g of sodium carbonate reacted with 6 g of ethanoic acid to from 8.2 g sodium ethanoate. 2.2 g carbon dioxide and 0.9 g water. Show that this data verifies the law of conservation of mass.
13. Define the molecular mass. Calculate the molecular mass of sulphuric acid and CH3COOH and C6H12O6.
Class –IX
Subject – Science (chemistry)
Answer the following questions:
1. What are metalloids? Give any two examples.
2. What is meant by the metals are sonorous.
3. write the formulas of thr following
Potassium sulphate, slacked lime, quick lime.
4. Define compounds, elements.
5. What are aqueous solutions?
6. State the principles of chromatography, crystallization, fractional distillation?
7. Give the symbols ( Dalton) of phosphorus, gold , sulphur, sodium?
8. Give the IUPAC symbol of silver, potassium, mercury, chlorine,magnesium?
9How will you differentiate b/w suspension and colloid?
10.If 110 gm of salt is present in 550 g of solution. Calculate the concentration of the solution.
11.What is the heating and cooling effect on solubility?
12.What do understand by condensation? Give any example.
13.How will you separate camphour, common salt, and iron nails from their mixture.
14.Define fractional distillation. Give an example.
15.State whether colloid solutions are homogeneous or heterogeneous.