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Class 10 · Science · Medium
→A sample gives carbon dioxide with acid and its aqueous solution turns red litmus blue. Which substance is most likely?
Class 10 · Science · Medium
→An aqueous solution of a salt turns red litmus blue. From which pair is this salt more likely to be formed?
Class 10 · Science · Hard
→If the pH of a basic solution changes from 12 to 9, which statement about the effect of hydroxide ions is most correct?
Class 10 · Science · Hard
→A student passes dry hydrogen chloride over dry blue litmus and observes no change. The same gas turns moist blue litmus red. What is the correct reason?
Class 10 · Science · Hard
→Two solutions have pH values 2 and 6 respectively. How much greater is the hydrogen ion concentration in the first solution than in the second?
Class 10 · Science · Hard
→A solution gives one gas with zinc and another gas with sodium carbonate. What is the correct identification of both gases?
Class 10 · Science · Hard
→A student says all acids give the same amount of hydrogen gas with metals. Why is this statement wrong?
Class 10 · Science · Medium
→If a basic substance is highly soluble in water and can burn skin, how should it be used in the laboratory?
Class 10 · Science · Medium
→If a solution has more hydroxide ions and fewer hydrogen ions, what colour may universal indicator show?
Class 10 · Science · Medium
→When an acidic solution is neutralised by a base, what determines the nature of the salt formed?
Class 10 · Science · Medium
→Which substance is important in both disinfecting and bleaching uses?
Class 10 · Science · Medium
→A solution is diluted slowly, but its pH does not move far from 7 because it was already neutral. Which solution could it be?
Class 10 · Science · Medium
→Methyl orange is red and phenolphthalein is colourless in a solution. What is the nature of the solution?
Class 10 · Science · Hard
→Which statement about chemical products related to common salt is correct?
Class 10 · Science · Easy
→What is a water-soluble base called?
Class 10 · Science · Medium
→Lime is added to improve acidic soil. What problem can occur if too much lime is added?
Class 10 · Science · Hard
→If the hydrogen ion concentration in a solution increases ten times, what happens to the pH?
Class 10 · Science · Medium
→Sour food should not be stored in copper vessels. What is the scientific reason?
Class 10 · Science · Hard
→Why did the risk increase when a student added water to acid for dilution?
Class 10 · Science · Medium
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