Chemistry
(a) A solution has a pH of 7. Explain how you would: (i) increase it's pH (ii) decrease it's pH.
(b) If a solution changes the colour of litmus from red to blue, what you can say about it's pH.
(c) What you can say about the pH of a solution, that liberates carbon dioxide from sodium carbonate?
Acids Bases Salts
70 Likes
Answer
(a) A solution with pH of 7 is neutral. (i) Increasing it's pH means increasing its basic nature. Hence, we will add alkali to increase it's pH. (ii) Similarly, to decrease it's pH, we will add an acid to the solution.
(b) When a solution changes the colour of litmus from red to blue, it shows it is basic in nature and the pH value will be more than 7.
(c) Acids liberate carbon dioxide on reaction with metallic carbonates and bicarbonates. Hence, the pH of this solution will be less than 7.
Answered By
42 Likes
Related Questions
Assertion (A): Iron (III) chloride is stored in a moisture proof container.
Reason (R): Iron (III) chloride is hygroscopic in nature.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Assertion (A): Water is added to acids to dilute them.
Reason (R): The addition of water to acids is a highly exothermic reaction. Splashes of acid solution may come in contact with skin and container may also break.
- Both A and R are true and R is the correct explanation of A.
- Both A and R are true but R is not the correct explanation of A.
- A is true but R is false.
- A is false but R is true.
Match the following:
Column A Column B (i) Acid salt (A) Ferrous ammonium sulphate (ii) Double salt (B) Contains only ions (iii) Ammonium hydroxide solution (C) Sodium hydrogen sulphate (iv) Dilute hydrochloric acid (D) Contains only molecules (v) Carbon tetrachloride (E) Contains ions and molecules Match the salts given in column I with their method of preparation given in column II.
Column I Column II (i) Pb(NO3)2 from PbO (A) Simple displacement (ii) MgCl2 from Mg (B) Titration (iii) FeCl3 from Fe (C) Neutralization (iv) NaNO3 from NaOH (D) Precipitation (v) ZnCO3 from ZnSO4 (E) Combination