Advertisements
Advertisements
प्रश्न
The number of molecules of water of crystallisation present in washing soda crystals is:
(a) five
(b) two
(c) ten
(d) seven
उत्तर
ten
The chemical formula of washing soda is Na2CO3.10H2O. The water molecules that form part of the structure of a salt are called its water of crystallisation. Hence, the number of molecules of water of crystallisation present in washing soda crystals is 10.
APPEARS IN
संबंधित प्रश्न
Complete and balance the following chemical equations:
`NaCI (aq) + H_2O (l) `
Write the names, formulae and colours of any two hydrated salts.
The aqueous solution of one of the following salts will turn red litmus to blue. This salt is:
(a) potassium sulphate
(b) sodium sulphate
(c) sodium chloride
(d) potassium carbonate
P and Q are aqueous solutions of sodium chloride and sodium hydroxide, respectively. Which of these will turn:
(a) blue litmus red?
Consider the following salts:
Na2CO3, NaCl, NH4Cl, CH3COONa, K2SO4, (NH4)2SO4
Which of salts will give:
acidic solutions?
What is a ‘salt’?
State one observation for each of the following :
Lead nitric is heated strongly in a test tube.
The Salt Story
From: The New Indian Express 9 March 2021
The salt pans in Marakkanam, a port town about 120 km from Chennai are the third largest producer of salt in Tamil Nadu. Separation of salt from water is a laborious process and the salt obtained is used as raw materials for manufacture of various sodium compounds.
One such compound is Sodium hydrogen carbonate, used in baking, as an antacid and in soda acid fire extinguishers.
The table shows the mass of various compounds obtained when 1litre of sea water is evaporated.
| COMPOUND | FORMULA | MASS OF SOLID PRESENT /g |
| Sodium Chloride | NaCl | 28.0 |
| Magnesium Chloride | MgCl2 | 8.0 |
| Magnesium Sulphate | MgSO4 | 6.0 |
| Calcium Sulphate | CaSO4 | 2.0 |
| Calcium Carbonate | CaCO3 | 1.0 |
| TOTAL AMOUNT OF SALT OBTAINED | 45.0 | |
How many grams of Magnesium Sulphate are present in 135g of solid left by evaporation of sea water?
Name the salt formed when sulphuric acid is added to sodium hydroxide and write its pH.
You are provided with the list of chemicals mentioned below in the box:
| Sodium hydroxide solution, copper carbonate, zinc, hydrochloric acid, copper, dilute sulphuric acid, chlorine, iron |
Using suitable chemicals from the list given, write a balanced chemical equation for the preparation of the salt mentioned below:
Copper sulphate
