Brown bottles??

Question

呢三樣野,邊樣要放入brown bottles??
1. potassium permanganate solution
2.concentrated sulphuric acid
3.concentrated nitric acid

我想知邊點解? 唔該!! (得同唔得的原因)) thanks

但係呢題個solution 唔知點解話3 係唔得, 係唔係個佢給的ANS 錯左??

Answer 1

If a reagent is sensitive to light, it should be stored in brown bottles. This is because a brown bottle can protect the reagent inside from exposure to light.

1 (KMnO4 solution) decomposes in light, and thus it should be stored in brown bottles.
2KMnO4(aq) → K2MnO4(aq) + MnO2(s) + O2(g) [in light]

2 (conc. H2SO4) is stable in light, and thus it is not necessary to store it in brown bottles.

3 (conc. HNO3) decomposed in light, and thus it should be stored in brown bottles.
4HNO3(aq) → 2H2O(l) + 4NO2(g) + O2(g) [in light]