HARD
9th CBSE
IMPORTANT
Earn 100
Classify the following into elements, compounds and mixtures.
(a) Calcium
(b) Water
(c) Dry ice
(d) Milk
(e) Soil
(f) Soap
Important Questions on Is Matter Around Us Pure? (Elements, Compounds and Mixtures)
EASY
9th CBSE
IMPORTANT
Classify the following as chemical and physical change:
Cooking of food.
MEDIUM
9th CBSE
IMPORTANT
Classify the following as chemical and physical change:
Heating platinum.MEDIUM
9th CBSE
IMPORTANT
Classify the following as chemical and physical change:
Freezing of water is _____ change. (Chemical/ Physical)
EASY
9th CBSE
IMPORTANT
Classify the following as chemical and physical change:
Drying of clothes is _____ change. (Chemical/Physical)
MEDIUM
9th CBSE
IMPORTANT
Classify the following as chemical and physical change:
Mixing of iron nails and sand is _____ change. ( Chemical/Physical)
EASY
9th CBSE
IMPORTANT
Classify the following as chemical and physical change:
Burning of methane is _____ change. (Chemical/ Physical)
HARD
9th CBSE
IMPORTANT
Name the special properties of a colloidal system which are not shown by a true solution.
HARD
9th CBSE
IMPORTANT
A student tested the solubility of different substances in water at different temperatures and collected the data as given below.
| Substance dissolved |
Temperature in K 283 293 313 333 353 Solubility |
||||
| 1. Potassium nitrate | 21 | 32 | 62 | 106 | 167 |
| 2. Sodium chloride | 36 | 36 | 36 | 37 | 37 |
| 3. Potassium chloride | 35 | 35 | 40 | 46 | 54 |
| 4. Ammonium chloride | 24 | 37 | 41 | 55 | 66 |
The solubility values in the table are given as grams of substance dissolved in 100 grams of water to form a saturated solution. Now answer the following question:
What mass of potassium nitrate would be needed to produce its saturated solution in 50 grams of water at 313 K?
