When substance A reacts with water it produces a combustible gas B and a solution of substance C in water. When another substance D reacts with this solution of C, it also produces the same gas B on warming but D can produce gas B on reaction with dilute sulphuric acid at room temperature. A imparts a deep golden yellow colour to a smokeless flame of Bunsen burner. A, B, C, and D respectively are
(a) Na, H2, NaOH, Zn
(b) K, H2, KOH, Al
(c) Ca, H2, Ca(OH)2, Sn
(d) CaC2, C2H2, Ca(OH)2, Fe
Correct answer: (a) Na, H2, NaOH, Zn
Explanation:
2Na + 2H2O → 2NaOH + H2↑
'A' 'C' 'B'
Zn + 2NaOH → Na2ZnO2 + H2↑
'D' 'C' 'B'
Zn + dil.H2SO4 → ZnSO4 + H2↑
'D' 'B'
Na produces golden yellow colour with smokeless flame of Bunsen burner.