Question

1. The following are statements about flames some of them are true while others are

Answer 1

Answer:

i)The carbon particles are formed when the gas is not completely burnt(True)

ii)A solid or liquid must be change to gaseous state in order to make flame(TRUE)

iii)A non- luminous Bunsen flame produces has three visible regions(FALSE)

iv)The luminous Bunsen flame produces less soot than the non- luminous flame(FALSE)

v)A yellow Bunsen flame is obtained when the air holes are opened(FALSE)

vi)The luminous Bunsen flame is hotter than a non- luminous Bunsen flame(FALSE)

vii)Bunsen burner uses kerosene as a source of heat(FALSE)

Explanation:

i)When the incomplete combustion ,then CO(carbon monoxide) and C(carbon) are produced. The unburnt carbon get deposited as Soot.

In complete combustion CO2(carbon dioxide) is produced.

ii)Fire, is the mixture of hot gases.Flame are result of chemical reaction between oxygen and fuel(e.g butane ,wood).Flame contain,carbon dioxide , heat ,light,steam.

iii)There are total three regions of flame in which the outer most region is the non-luminous .The non-luminous part is blue(one visible region) and does not emit-light.

iv) Luminous Bunsen flame produces more soot than the non- luminous flame because luminous flame contain more unburnt particles as compare to non-luminous.

luminous part has less oxygen available for complete combustion of fuel

v)When the air hole is open it means excess oxygen is supplied to the fuel.

In this case clean and luminous flame is produced.When air hole is close yellow flame is produced.

vi)Non-luminous part of flame is more hot because of complete combustion due to proper availability  of oxygen. Sometime the particle of non-luminous flame get ionize also.

vii).The bunsen burner uses Natural gas(methane) or LPG(propane and butane)as sources of heat because these are easily burnt not kerosene.