Most important questions, class 9th

  1. Differentiate between mixtures and compound by giving appropriate examples?
  2. Write a method to separate a mixture of salt and ammonium chloride?
  3. What is crystallization? Where is it used? Why is this better than simple evaporation technique?
  4.  What is chromatography? What are its various applications and underline the basic principle involved?
  5. A solution of H2SO4 acid is labeled is 95%. What is the mass of this that must be diluted with water to get 5L of solution containing 10g of H2SO4 per litre?
  6. Which of the following solution scatter light? (a) colloidal solution  (b) suspension (c) both  (d) none
  7. Which of the following methods would you use to separate cream from milk?(a) fractional distillation  (b) distillation (c) centrifugation (d) filtration
  8. Cooking of food and digestion of food:-(a) are both physical processes  (b) are both chemical processes (c) cooking is physical whereas digestion is chemical  (d) cooking is chemical whereas digestion physical
  1. Mercury and Bromine are both (a) liquid at room temperature   (b) solid at room temperature (c) gases at room temperature  (d) both (a) and (b) 
  2. What is a mixture? What are its various types?
  3. Define solute, solvent and solution?
  4. What is a solution? What are the properties of solution?
  5. Differentiate between elements and compounds.
  6. Write a method to separate different gases from air.
  7. What is a colloid? What are its various properties?
  8. A solution contains 60g of NaCl in 400g of water. Calculate the concentration in term of mass by mass percentage of the solution.
  9. Differentiate between metals and non metal based upon the various properties that they show.
  10. What is distillation and fractional distillation? What is the basic property that separates the two methods?