What do you understand by composite fish culture?
Composite fish culture is a most popular technique to obtain maximum yield of fish from a pond/reservoir. The technology involves employment of compatible and non-competing fish culture through utilisation of different feeding zones of the pond or reservoir, resulting in maximum production of fish per unit area of water. It is accomplished in four steps i.e. Pre stocking, Stocking, Post stocking and harvesting.
Example: Surface feeders such as Catlas are mixed with column feeders such as Rohus, Mrigals, Grass Carp which are bottom feeders. This combination leads to an efficient utilisation of food present in the pond and enhances the yield of fish from pond.
Pragya tested the solubility of three different substances at different temperatures and collected the data as given below (results are given in the following table, as grams of substance dissolved in 100 grams of water to form a saturated solution).
Substance Dissolved | Tem | per | atu | re | in K |
283 | 293 | 313 | 333 | 353 | |
Potassium nitrate | 21 | 32 | 62 | 106 | 167 |
Sodium chloride | 36 | 36 | 36 | 37 | 37 |
Potassium chloride | 35 | 35 | 40 | 46 | 54 |
Ammonium chloride | 24 | 37 | 41 | 55 | 66 |
(a) What mass of potassium nitrate would be needed to produce a saturated solution of potassium nitrate in 50 grams of water at 313 K?
(b) Pragya makes a saturated solution of potassium chloride in water at 353 K and leaves the solution to cool at room temperature. What would she observe as the solution cools? Explain.
(c) Find the solubility of each salt at 293 K. Which salt has the highest solubility at this temperature?
(d) What is the effect of change of temperature on the solubility of a salt?
NCERT questions are designed to test your understanding of the concepts and theories discussed in the chapter. Here are some tips to help you answer NCERT questions effectively:
Welcome to the NCERT Solutions for Class 9 Science - Chapter . This page offers a step-by-step solution to the specific question from Excercise 0 , Question 41: What do you understand by composite fish culture?....
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