Q1.Why Does the rate of evaporation of a liquid increases on heating ?
Q2.How during burning of a candle , both physical and chemical changes takes place ?
Q8. A Gas Jar is upside down on a gas jar of boromin vapour. it is observerd that the gas jar containing air also becomes completely reddish brown.
- 1.Explain Why ?
- 2.Name the Process
Q9. Describe in brief an activity to show sublimation of ammonium chloride with the help of Labelled diagram.
Q10. Cough syrup is common medicine of cold and cough and contains alcohol(ethanol) as one of its constituents.some peoples use it as alternative of wine.
- 1.What should the goverment do to prevent misuse of such medicines ?
- 2.which is the most common method for expressing concentration of a solution ?
Q11. Give two examples of the following :
- 1.Colloids.
- 2.Suspension.
- 3.True Solution.
Q19. Name the methods to seperate the following :
- 1.Nitrogen from air.
- 2.Dye from blue ink.
- 3.Cream from Milk.
- 4.Ammonium chloride from common salt.
Q24.Compare in tabular from the properties of solids,liquids and gases with respect to
- 1.Shape
- 2.Volume
- 3.Compressibilty
- 4.Diffusion
- 5.Fludity or rigidty
Q28.Metanil yellow is
- a.Dye used in textile industry
- b.Chemical used in laundry
- c.Acid used in neutralisation reactions
- d.Salt formed aftre a neutralisation reaction between an acid and a base
Q29.Following Substances are added to water in a beaker as shown.the mixture is stirred well. A true solution is found in the beaker
Q30. Ritu added a few drops of iodine solution to test tubes A,B and C Containing food Samples.She observed a blue-black colour appeared in test tubes A and C.what was the correct order of food samples in the test tubes.
- a.Potato,dal,dal
- b.Rice,Potato,dal
- c.Rice,dal,potato
- d.Potato,potato,rice
Q33. Starch test gives blue-black colour because starch reacts with iodine to form which of the following
- A.Glucose-potassium complex
- B.Starch-carbon complex
- C.Starch-iodine complex
- D.Glucose-potassium complex
Q35.Which one of the following experimental setups is correct for the determination of the boiling point of water ? Why ?
