Q.4 Name or state the following. 1. An efflorescent decahydrate salt. 2. A deliquescent salt of a trivalent metal. 3. A liquid hygroscopic substance. 4. A salt whose solubility decreases with rise in temperature of the solvent water. 5. A substance added to remove both temporary & permanent hardness in water. C11
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1. Na2CO3.10H2ONa2CO3.10H2O- An efflorescent substance in chemistry is a hydrated molecule which have water associate with it molecule. When it is exposed to air, it gets dehydrated. Na2CO3.10H2ONa2CO3.10H2O Loses nine water molecules and finally becomes completely anhydrous.
2. AlCl3orAuCl3AlCl3orAuCl3 - a deliquescent salt is a hygroscopic salt, which absorbs water from the surrounding.
3. Glycerine or methanol – a hygroscopic substance makes attachment of water through its surface either through adsorption or absorption.
4. CaSO4CaSO4 - calcium sulphate is the salt which solubility decreases with increasing the temperature.
5. Washing soda Na2CO3Na2CO3 - Washing soda removes both temporary and permanent hardness of water by converting calcium and magnesium compound into insoluble carbonates. In place of sodium carbonate, caustic soda or sodium phosphate can also be used.
So, the correct answer is “Option B”.
Explanation:
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