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Displaying 5 out
of 66
questions & answers.
Q1.
Complete and balance the equations
HARD & SOFT WATER a. Formation of temporary hard water |
CaCO3 + H2O + CO2 → ___________ |
| b. Removal of temporary hardness in water - by boiling | Ca(HCO3)2 → ___________ ↓ + ___________ +___________ [g] |
| c. Removal of temporary hardness in water - by addition of washing soda [Na2CO3] | Na2CO3 + Ca(HCO3)2 → ___________ ↓ + ___________ |
| d. Removal of permanent hardness in water - by addition of washing soda [Na2CO3] | Na2CO3 + CaSO4 → ___________ ↓ + ___________ |
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Answer:
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- Ca(HCO3)2
- Mg(HCO3)2
- CaCO3 + H2O + CO2
- MgCO3 + H2O + CO2
- CaCO3 + 2NaHCO3
- CaCO3 + Na2SO4
Q2.
Name one substance which is 'deliquescent'.
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Answer:
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Calcium Chloride.
Q3.
How does an increase in temperature affect:
- the solubility of NaCl,
- the solubility of CaSO4 in water?
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- Increase slightly with rise in temperature.
- Decreases with rise in temperature
Q4.
Table salt becomes moist and sticky during the rainy season. Give reasons.
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answer not shownQ5.
A white powder forms on the surface of washing soda crystals which are left exposed to the air. Give reasons.
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