Section A: Indicators & Colors
Q1-10. Complete the table or fill in the blanks:
- Blue Litmus turns __________ in Acid.
- Red Litmus turns __________ in Base.
- Color of Phenolphthalein in Acid is __________.
- Color of Phenolphthalein in Base is __________.
- Color of Methyl Orange in Acid is __________.
- Color of Methyl Orange in Base is __________.
- Turmeric solution turns __________ in soap solution.
- Litmus is extracted from __________.
- Olfactory indicators change their __________ in acidic or basic media.
- Vanilla essence smell __________ (remains/vanishes) in NaOH solution.
Section B: Basics & Definitions
Q11-20. Fill in the blanks:
- Acids taste __________.
- Bases taste __________ and feel __________ to touch.
- Water soluble bases are called __________.
- Reaction between an Acid and a Base is called __________ reaction.
- Metallic oxides are __________ in nature.
- Non-metallic oxides are __________ in nature.
- All acids contain __________ ion.
- All bases contain __________ ion.
- Dilution of acid is an __________ (exothermic/endothermic) process.
- Curd contains __________ acid.
Section C: Key Reactions
Q21-25. Complete the general word equations:
- Acid + Metal $\rightarrow$ Salt + __________
- Acid + Metal Carbonate $\rightarrow$ Salt + Water + __________
- Acid + Metal Oxide $\rightarrow$ Salt + __________
- Base + Non-Metal Oxide $\rightarrow$ Salt + __________
- NaOH + HCl $\rightarrow$ __________ + Water
Section D: The pH Scale
Q26-35. Answer briefly:
- What is the pH of pure water? __________
- Solutions with pH < 7 are __________ (Acidic/Basic).
- Solutions with pH > 7 are __________ (Acidic/Basic).
- Which is a stronger acid: pH 2 or pH 5? __________
- Which is a stronger base: pH 8 or pH 13? __________
- Tooth decay starts when pH of mouth falls below __________.
- Stinging hair of nettle leaves inject __________ acid.
- pH of Acid Rain is less than __________.
- Our stomach produces __________ acid to help digestion.
- To treat acidity, we use mild bases called __________.
Section E: Common Salts & Formulae
Q36-45. Write the Chemical Formula for:
- Common Salt: __________
- Caustic Soda: __________
- Baking Soda: __________
- Washing Soda: __________
- Bleaching Powder: __________
- Plaster of Paris: __________
- Gypsum: __________
- Slaked Lime: __________
- Quick Lime: __________
- Lime Water: __________
Section F: Chemical Names
Q46-50. Write the Chemical Name for:
- $NaHCO_3$: __________
- $Na_2CO_3 \cdot 10H_2O$: __________
- $CaOCl_2$: __________
- $CaSO_4 \cdot \frac{1}{2}H_2O$: __________
- $CuSO_4 \cdot 5H_2O$: __________