📚 CBSE Grade-10 Study Guide Open in the Study Guide single page app →
HomeScience

Science — CBSE Class 10 board question

Q1. [5]
Answer the following:
  1. (i) Five solutions A, B, C, D and E when tested with pH paper showed pH as 4, 1, 13, 7 and 10 respectively. Which solution is : (1) Strongly acidic (2) Strongly alkaline (3) Weakly acidic (4) Neutral and (5) Weakly alkaline ? Arrange the solutions in increasing order of H⁺ ion concentration.
  2. (ii) Write the name and formula of (1) an acidic salt and (2) a basic salt giving the name of the parent acid and parent base used to form the salt in each case.
Previously asked in CBSE board exam
2024 31/3/1 Q34(a)
Generated by claude-sonnet-4-6 · 2026-06-15 06:46 · grounding rag
Model Answer

(i)

| Solution | pH | Type |
|---|---|---|
| B | 1 | (1) Strongly acidic |
| C | 13 | (2) Strongly alkaline |
| A | 4 | (3) Weakly acidic |
| D | 7 | (4) Neutral |
| E | 10 | (5) Weakly alkaline |

Increasing order of H⁺ ion concentration (lower pH → higher H⁺):

$$C < E < D < A < B$$

(pH 13 < 10 < 7 < 4 < 1)

---

(ii)

(1) Acidic Salt:
Name: Sodium bisulphate (Sodium hydrogen sulphate)
Formula: NaHSO₄
Parent acid: Sulphuric acid (H₂SO₄) — strong acid, partially neutralised
Parent base: Sodium hydroxide (NaOH)

(2) Basic Salt:
Name: Basic copper chloride (Copper hydroxychloride)
Formula: Cu(OH)Cl
Parent acid: Hydrochloric acid (HCl)
Parent base: Copper hydroxide [Cu(OH)₂] — strong base, partially neutralised

---

Explanation
If a question refers to an image, map, graph or diagram that is not shown here, open the Study Guide single page app, go to Library and find the actual CBSE question paper. The original papers are also available on the CBSE website: cbse.gov.in.
Previous-year CBSE Grade 10 board exam questions, organised by subject and chapter, each with a model answer — free to read and print.