Question

It describes the properties of dangerous goods, but which of the following is incorrect? (1) Yellow phosphorus is a white or pale yellow aromatic waxy solid. (2) Calcium phosphide is a reddish brown lump and reacts with water to produce toxic gas. (3) Calcium carbide is pure white solid. When nitrogen is passed at a constant temperature, it becomes lime nitrogen. (4) Sodium is a bright silver-white metal with a specific gravity of less than 1. (5) Potassium is a bright silver-white soft metal with a specific gravity of less than 1 and a lower melting point and boiling point than sodium.

Answer 1

Statement 1 is incorrect because yellow phosphorous is a type of phosphorous with a formula of P₄. It does not contains any aromatic waxy solid

So, option 1 is the right option, Yellow phosphorus is a white or pale yellow aromatic waxy solid

Option 2 is correct because Calcium phosphide is a reddish brown lump and reacts with water to produce phosgene as a toxic gas

Option 3 is correct because Calcium carbide is pure white solid, when nitrogen is passed at a constant temperature, it becomes lime nitrogen or nitrolime, and the reaction is shown below:

CaC₂ + N₂ ----------------> CaCN₂ + C

Option 4 is correct because Sodium is a bright silver-white metal with a specific gravity of 0.968

Option 5 is correct because Potassium is a bright silver-white soft metal with a specific gravity of 0.862 with melting point of 63 ^oC and boiling point of 760 ^oC where sodium has melting point of 370 ^oC and boiling point of 1156 ^oC.