Physics, Chemistry and Biology: Post your doubts here!

[Ironheart]

How do i separate hexane from a mixture of hexane and octane?

 

[Awesome12]

How do i separate hexane from a mixture of hexane and octane?

Octane has a higher boiling point than hexane. So you could separate them by fractional distillation

 

[shoaib672002]

Plz solve all and with diagrams

Awesome12

 

[dubi2pro]

the 24th one please why and how is the answer 3.0 mol/dm??

 

[Awesome12]

the 24th one please why and how is the answer 3.0 mol/dm??

Take the readings for the max temp
Moles of HCl = 2.0 * (3/1000)
=0.06

Moles of HCl = Moles of NaOH
0.06 = 0.06

0.06 = Conc. * (20/1000)
Conc. = 3.0 mol/dm^3

 

[Phoenix Blood]

???

 

[Awesome12]

???

A body is stationary or travelling with constant speed only when the forces acting on it are equal

 

[Phoenix Blood]

What sort of soluble substances?

 

[Phoenix Blood]

What justifies the answer? :/

 

[shoaib672002]

dude from which past papers

2013 may june

 

[Awesome12]

What sort of soluble substances?

Pure water is tasteless. So in order to retain the taste, minerals are added

 

[Awesome12]

What justifies the answer? :/

The answer is D
Akalis liberate ammonia when they react with Ammonium Salts
Acids turn litmus red

 

[princess sofia]

cn any1 plz answer thx
part(ii)

 

[Awesome12]

cn any1 plz answer thx
part(ii)View attachment 39303

lets assume the ball has a mass of 3.0 kg
Its Ep = mgh
Ep = 3.0 (10) (4.0)
Ep =120 J

22% of energy is lost
thus, the ball now has: 120*22 /100
= 120-26.4
=93.6 J

The mass and g remain constant

93.6 = 3.0 * 10 * h
Find h

 

[Mavilda Bucket]

why detergents need to be biodegradable and why dont they form a scum????

 

[mushiii]

hello, can someone help me in chemisty paper 3 october november 2007 Question 6 iv

 

[mushiii]

i checked the mark scheme and it says to plot points

 

[agha saad 22]

I need notes for ELECTROPHORESIS ! i missed one lecture plzzzzzzzzzzzzzzzzzzzzzzzzzz help me!!! en FINGERPRINTING Too

 

[Phoenix Blood]

???

 

[Phoenix Blood]

?