21. | The P°H° of fresh milk is pH₆, when it turns sour, its P°H° (pH) |
A. < 6 will be | |
B. remains the same i.e. 6 | |
C. > gets 6 | |
D. becomes indifferent i.e. 7 |
22. | P ° H ° (pH) shows |
A. Chemical used in making photographs from negative | |
B. value of acidity or alkalinity of a solution | |
C. earthquake intensity rating | |
D. evaluation of purity of milk |
23. | Aqueous solution of ammonium chloride is |
A. acidic | |
B. alkaline | |
C. Moody | |
D. Colorful |
24. | Solutions in test tubes containing H₂O and aqueous NaOH can be distinguished from – |
A. by red litmus | |
B. by blue litmus | |
C. Na₂CO₃ | |
D. by aqueous HCI |
25. | Which of the following is an acidic salt? |
A. HCIO | |
B. AgBr | |
C. HFN | |
D. HCO₃ |
26. | Aqueous solution of which of the following salts turns red litmus blue? |
A. Na₂CO₃ | |
B. NaHCO₃ | |
C. Na₂CO₃ ,10H₂O | |
D. all of the above |
27. | Which instrument is used to test the acidity of an aqueous solution? |
A. hygrometer | |
B. acidometer | |
C. Ph meter | |
D. ammeter |
28. | Which of the following compound is not a Lewis acid? |
A. HERE₃ | |
B. BF₃ | |
C. NH₃ | |
D. FeCI₃ |
29. | The pH value of pure water is |
A. 0 | |
B. 1 | |
C. 7 | |
D. 14 |
30. | acid is a substance that |
A. accepts electrons | |
B. provides electrons | |
C. gives proton | |
D. gives OH ion |