Biology; Chemistry; Physics: Post your doubts here!

[MustafaMotani]

it should be iodine no??
they are talking about molecular structure keeping in mind one molecule!

yeah so carbon have molecular structures like diamond and graphite

 

[syed1995]

it should be iodine no??
they are talking about molecular structure keeping in mind one molecule!

I don't know the answer .. Iodine is what i thought too .. no marking scheme available

2003 Question

 

[MustafaMotani]

So i told u why ... :S :-\

 

[SALT]

someone give the precise answer,i also want to know it........

fractional distillation---occurs on the principle of different boiling points of different fractions
air liquefied by cooling to approximately 250 degree celcius
water vapour and co2 are not present in the liquefied mixture(water freezes at 0 and co2 solidifies at 80)
the contents are then warmed up
the gases boil off when their boiling point is achieved
the vapours are then condensed to obtain separate fractons

 

[syed1995]

Water Supplies are obtained from rivers, boreholes and reservoirs. The water must be treated before use.

Describe and explain the two main processes in the purification of water supplies [4 Marks]

 

[MustafaMotani]

fractional distillation---occurs on the principle of different boiling points of different fractions
air liquefied by cooling to approximately 250 degree celcius
water vapour and co2 are not present in the liquefied mixture(water freezes at 0 and co2 solidifies at 80)
the contents are then warmed up
the gases boil off when their boiling point is achieved
the vapours are then condensed to obtain separate fractons

they are cooled to 200 C and helium and neon are not liquified till this temp

 

[MustafaMotani]

Water Supplies are obtained from rivers, boreholes and reservoirs. The water must be treated before use.

Describe and explain the two main processes in the purification of water supplies [4 Marks]

Filtration and Chlorination and Addition of flourine, ull get one mark for explaing..

 

[syed1995]

they are cooled to 200 C and helium and neon are not liquified till this temp

-274 = one K right ? what is this temperature? the temperature at which absolutely nothing is left.?

 

[syed1995]

Filtration and Chlorination and Addition of flourine, ull get one mark for explaing..

Addition of Flourine?!?

 

[Spidey21]

-274 = one K right ? what is this temperature? the temperature at which absolutely nothing is left.?

0 *c = 1 K

 

[syed1995]

0 *c = 1 K

Nope.

 

[Spidey21]

-273 *c = 0 K

 

[MustafaMotani]

Addition of Flourine?!?

Flourine is aded coz its good for teeth

 

[MustafaMotani]

C = k - 273 I guess

 

[Spidey21]

http://wiki.answers.com/Q/What_is_1_degree_Celsius_in_Kelvin

Nope.

 

[syed1995]

C = k - 273 I guess

yea but there was something special about the temperature -273 .. i remember our teacher telling us somethin about it :<

 

[Spidey21]

C = k - 273 I guess

Nope.

easier way to remember is that 0 kelvin is touched when the particles lose energy completly...which has never been achieved...and -273 *c = 0 K

 

[Spidey21]

yea but there was something special about the temperature -273 .. i remember our teacher telling us somethin about it :<

easier way to remember is that 0 kelvin is touched when the particles lose energy completly...which has never been achieved...and -273 *c = 0 K

You are talking to a person who loves quantum Physics

 

[MustafaMotani]

-274 = one K right ? what is this temperature? the temperature at which absolutely nothing is left.?

- 273

 

[MustafaMotani]

Nope.

speciality is that it is unattainable..