Day 121: CBSE Class 10 Science

5 questions (8 parts). Try each one first, then open its answer.

Question 1
Acids, Bases and Salts. Asked once: 2023 (same type asked 3 times)
4 $Fresh milk has a pH of 6. To delay its curdling, a chemical substance is added to it, which is :$
Tap an option to check your answer.
Question 2
Acids, Bases and Salts. Asked once: 2025 (same type asked 3 times)
2 $Which of the given option represents a family of salts ?$
Tap an option to check your answer.
Question 3
Acids, Bases and Salts. Asked once: 2024 (same type asked 3 times)
2 $The acid produced in our stomach during digestion and the base used to neutralise the excess acid during indigestion respectively are :$
Tap an option to check your answer.
Question 4
Acids, Bases and Salts. Asked once: 2025 (same type asked 3 times)
28 (a) $In an experiment a student dipped pH papers in four different solutions A, B, C and D and reported his observation as given below : Solution A B C D Colour of pH paper Light green Blue Green Red (i) In which one of these solutions is the concentration of (1) hydrogen / hydronium ions; (2) hydroxyl ions maximum ? (ii) Give one example each of the two solutions identified in (i) above. (iii) What would be the pH of the resultant mixture obtained when these two solutions are mixed together in equal proportions ? Justify your answer.$
Question 5 (case study, 4 parts)
Acids, Bases and Salts. Asked once: 2023 (same type asked 3 times)
The teacher while conducting practicals in the laboratory divided the students into three groups and gave them various solutions to find out their pH and classify them into acidic, basic and neutral solutions. Group A – Lemon juice, vinegar, colourless aerated drink Group B – Tomato juice, coffee, ginger juice Group C – Sodium hydroxide, sodium chloride, lime water
37 (a) $For the solutions provided, which group is/are likely to have pH value (i) less than 7, and (ii) greater than 7 ?$
37 (b) $List two ways of determining pH of a solution$
37 (c) $Explain, why the sour substances such as lemon juice are effective in cleaning the tarnished copper vessels.$
37 (c) OR $“pH has great importance in our daily life.” Justify this statement by giving two examples.$

Question 1

Question 2

Question 3

Question 4

Question 5 (case study, 4 parts)