std 9 varshik pariksha 2022 science paper solution , ધોરણ 9 વિજ્ઞાન પેપર વાર્ષિક પરીક્ષા 2022, std 9

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.

(Investment to be made for Redemption of Debentures). X Ltd. Had issued on 1st April, 2016, 20,000, 9% Debentures of Rs. 100 each redeemable by draw of lots as under : (i) During the ending on 31st March, 2018 - 15% (ii) During the ending on 31st March, 2019 - 25% (iii) During the ending on 31st March, 2020 - 15% (iv) During the ending on 31st March, 2021 - 21% (i) During the ending on 31st March, 2022 - 20% What is the minimum investment or deposit that should be made by X Ltd. as per the Conpanies Act, 2013 before redemption of debentures and When ?

If (101 pi)/(9) radians is equal to x^(0) then x is 2020 2021 2022 2019