Plaster of Paris should be stored in a moisture-proof container. Explain why?
Plaster of Paris should be stored in a moisture-proof container. Explain why?
Solution and Explanation
Plaster of Paris (POP) should be stored in a moisture-proof container because Plaster of Paris, a powdery mass, absorbs water (moisture) to form a hard solid known as gypsum.
Top Questions on Chemical Properties Of Acids And Bases
A milkman adds a very small amount of baking soda to fresh milk.
(a) Why does he shift the pH of the fresh milk from 6 to slightly alkaline?
(b) Why does this milk take a long time to set as curd?- CBSE Class X
- Science
- Chemical Properties Of Acids And Bases
Compounds such as alcohols and glucose also contain hydrogen but are not categorized as acids. Describe an Activity to prove it.
- CBSE Class X
- Science
- Chemical Properties Of Acids And Bases
Give two important uses of washing soda and baking soda.
- CBSE Class X
- Science
- Chemical Properties Of Acids And Bases
What is a neutralization reaction? Give two examples.
- CBSE Class X
- Science
- Chemical Properties Of Acids And Bases
Fresh milk has a pH of 6. How do you think the pH will change as it turns into curd? Explain your answer.
- CBSE Class X
- Science
- Chemical Properties Of Acids And Bases
Questions Asked in CBSE X exam
- Explain various types of fire extinguishers and their extinguishing materials.
- CBSE Class X - 2024
- Fire extinguisher
- What are the solutions to hazards in respect of Electrical Rescue Techniques?
- CBSE Class X - 2024
- Electrical hazards
- Write some of the symptoms of exposure to toxins when a person has been exposed to chemical hazards in a workplace.
- CBSE Class X - 2024
- Chemical hazards
- Enlist the points to remember for working safely around electrical panels and cabinets.
- CBSE Class X - 2024
- Electrical hazards
- What do you know about the composition of a microwave oven?
- CBSE Class X - 2024
- Repair and Maintenance
Concepts Used:
Acids and Bases
Acid is any hydrogen-containing substance that is capable of donating a proton (hydrogen ion) to another substance. Base is an ion or molecule capable of accepting a hydrogen ion from acid.
Physical Properties of Acids and Bases
| Physical Properties | ACIDS | BASES |
| Taste | Sour | Bitter |
| Colour on Litmus paper | Turns blue litmus red | Turns red litmus blue |
| Ions produced on dissociation | H+ | OH- |
| pH | <7 (less than 7) | >7 (more than 7) |
| Strong acids | HCl, HNO3, H2SO4 | NaOH, KOH |
| Weak Acids | CH3COOH, H3PO4, H2CO3 | NH4OH |
Chemical Properties of Acids and Bases
| Type of Reaction | Acid | Bases |
| Reaction with Metals | Acid + Metal → Salt + Hydrogen gas (H2) E.g., Zn(s)+ dil. H2SO4 → ZnSO4 (Zinc Sulphate) + H2 | Base + Metal → Salt + Hydrogen gas (H2) E.g., 2NaOH +Zn → Na2ZnO2 (Sodium zincate) + H2 |
| Reaction with hydrogen carbonates (bicarbonate) and carbonates | Metal carbonate/Metal hydrogen carbonate + Acid → Salt + Carbon dioxide + Water E.g., HCl+NaOH → NaCl+ H2O 2. Na2CO3+ 2 HCl(aq) →2NaCl(aq)+ H2O(l) + CO2(g) 3. Na2CO3+ 2H2SO4(aq) →2Na2SO4(aq)+ H2O(l) + CO2(g) 4. NaHCO3+ HCl → NaCl+ H2O+ CO2 | Base+ Carbonate/ bicarbonate → No reaction |
| Neutralisation Reaction | Base + Acid → Salt + Water E.g., NaOH(aq) + HCl(aq) → NaCl(aq) + H2O(l) | Base + Acid → Salt + Water E.g., CaO+ HCl (l) → CaCl2 (aq)+ H2O (l) |
| Reaction with Oxides | Metal oxide + Acid → Salt + Water E.g., CaO+ HCl (l) → CaCl2 (aq)+ H2O (l) | Non- Metallic oxide + Base → Salt + Water E.g., Ca(OH)2+ CO2 → CaCO3+ H2O |
| Dissolution in Water | Acid gives H+ ions in water. E.g., HCl → H+ + Cl- HCl + H2O → H3O+ + Cl– | Base gives OH- ions in water. |
Read more on Acids, Bases and Salts