Acids, Bases, and Salts involves the study of the reactions of acids, bases, and salts. In this chapter, students will learn about the chemical properties of acids and bases, how acids and bases cancel each others effect, how acids and bases react with metals, reactions of metallic oxides acids, reactions of non-metallic oxides with bases, etc. All these concepts have been taught in detail on NTSEGuru video lectures. Our Chemistry Expert has compiled NTSE important questions to help students prepare for their exams better.
Q. Which one of the following oxides gives pink colour with phenolphthalein indicator in aqueous solution?
Ans. (c) CaO
Sol. Because CaO is basic in nature
Q. Strong electrolytes is –
Ans. (d) NaCl
Sol. NaCl because it dissociates completely on electrolysis
Q. Ammonium chloride is a salt of:
(a) Weak Acid and Weak Base
(b) Weak Acid and Strong Base
(c) Strong Acid and Strong Base
(d) Strong Acid and Weak Base
Ans. (d) Strong Acid and Weak Base
Sol. HCL + NH4OH → NH4Cl + H2O
Q. pH paper is separately dipped into 2 different solutions X and Y. Colour of pH paper turned pale green in X and blue in Y. X and Y are most probably:
(a) X – water, Y – NaOH
(b) X – NaOH, Y – H2O
(c) X – HCl, Y – NaOH
(d) X – NaOH, Y – HCl
Ans.(a) X – water, Y – NaOH
Sol. Water has PH = 7 (given pale green colour), NaOH is base PH = 9 (given blue).
Q. Why is gypsum added to cement?
(a) To undergo a chemical reaction.
(b) To dehydrate cement.
(c) To slow down the initial setting of cement.
(d) To make cement stronger.
Ans. (c) To slow down the initial setting of cement.
Sol. Gypsum, when added to cement, elongates the setting time of cement.
Students must pay extra attention to this chapter as it focuses on the fundamentals of Chemistry. Aforementioned questions are important for NTSE 2019. Stay tuned with NTSEGuru.in for important questions of Chapter 3.