AIEEE 2004 | p-Block Elements Question 249 | Chemistry

The soldiers of Napolean army while at Alps during freezing winter suffered a serious problem as regards to the tin buttons of their uniforms. White metallic tin buttons got converted to grey power. The transformation is related to :

a change in the partial pressure of oxygen in the air

a change in the crystalline structure of tin

an interaction with nitrogen of the air at very low temperature

an interaction with water vapor contained in the humid air

AIEEE 2003

MCQ (Single Correct Answer)

-1

Out of Syllabus

Concentrated hydrochloric acid when kept in open air sometimes produces a cloud of white fumes. The explanation for it is that :

oxygen in air reacts with the emitted HCI gas to form a cloud of chlorine gas

strong affinity of HCI gas for moisture in air results in forming of droplets of liquid solution which appears like a cloudy smoke

due to strong affinity for water, concentrated hydrochloric acid pulls moisture of air towards it self. This moisture forms droplets of water and hence the cloud.

concentrated hydrochloric acid emits strongly smelling HCI gas all the time.

AIEEE 2003

MCQ (Single Correct Answer)

-1

Glass is a :

super-cooled liquid

gel

polymeric mixture

micro-crystalline solid

AIEEE 2003

MCQ (Single Correct Answer)

-1