std 9 social science paper solution 2022,std 9 social science second annual exam pepar solution,std 9 social science second annual February 2022,dhoran 9 samajik vigyan paper solution February 2022,std 9 dritiy pariksha samajik vigyan paper solution

A student took a sodium salt and dissolved it in water. When this aqueous sodium salt solution was terted with universal indicator paper, its pH was found to be 9. (a) What does pH 9 tell us about the sodium salt solution. (b) Name one sodium salt which can produce such a solution.

You have four solutions A, B, C and D. The pH of solution A is 6, B is 9, C is 12 and D is 7. (a) Identify the most acidic and most basic solutions. (b) Arrange the above four solutions in the increasing order of H^+ ion concentration. (c) State the change in colour of pH paper on dipping in solution C and D.

(i) Explain why is hydrochloric acid a strong acid and acetic acid, a weak acid ? How can it be verfied ? (ii) Explain why equeous solution of an acid conducts electricity. (iii) You have four solutions A, B,C and D. The pH of solution A is 6, B is 9, C is 12 and D is 7. (a) Identify rhe most acidic and most basic solutions. (b) Arrange the above four solutions in the increasing order of H^(+) ion concentration. (c ) State the change in colour of pH paper on dipping in solution C and d.

(a). What effect does the concentration of H^(+) (aq) ions have on the nature of a solution? (b). What effect does the concentration of OH^(-) ions have on the nature of a solution? (c). Someone put some universal indicator paper into vinegar. The pH is 3. What does this tell you about the vinegar? (d). Someone put some universal indicator paper onto wet soap. the pH is 8. What does this tell you about the soap? (e). State whether a solution is acidic, alkali or neutral if its pH is: (i) 9 (ii) 4 (iii) 7 (iv) 1 (v) 10 (vi) 3.