111) When Na₂CO₃ reacts with an acid, which of the following gases is evolved

A) H₂
B) N₂
C) O₂
D) CO₂

112) An antacid is

A) a salt
B) an acid
C) a base
D) an acid or base

113) The nature of non-metal oxide is

A) acidic
B) basic
C) neutral
D) acidic or basic

114) Principal quantum number (n) is represented with

A) 0, 1, 2, 3,….
B) K, L, M,…..
C) X, Y, Z,…..
D) A, B, C,……

115) Which of the following properties was explained by Bohr’s atomic model

A) line spectra of H atom
B) fine spectra of H atom
C) both line and fine spectra of H atom
D) none of the above