[pr33ti]

Why is it important to use distilled water at temperature to carry out dilution experiments?

-Is it because it is more pure, but I do not understand why we need it at room temperature

[Yggdrasil]

The density of water varies with temperature, so if you want to be very accurate 100mL of water at RT will not have the same mass as 100mL of water at much lower or higher temperatures.

[pr33ti]

thank you so much 

so is water at room temperature denser or less dense?

[Yggdrasil]

In general, density decreases as temperature increases.  However, water is strange in that it expands when it freezes, so water is most dense at 4^oC.  Warming water up from 4^o will decrease its density and so will cooling it (until it freezes).

[english]

Warming water up from 4^o will decrease its density and so will cooling it (until it freezes).

Very strange stuff.  Never knew that.   

[pr33ti]

Using this renewed equation, we can see that density and temperature are indirectly proportional; as T increases, d decreases, as T decreases, d increases.

Use this equation!
               

most certainly I will.... thank you for the detailed explaination...

I have used the formula d= MP/RT recently for the Gas Problems...So it's still fresh in my memory

thank you again

[pr33ti]

In general, density decreases as temperature increases.  However, water is strange in that it expands when it freezes, so water is most dense at 4^oC.  Warming water up from 4^o will decrease its density and so will cooling it (until it freezes).

THANK YOU again! 

[english]

Using this renewed equation, we can see that density and temperature are indirectly proportional; as T increases, d decreases, as T decreases, d increases.

Use this equation!
               

most certainly I will.... thank you for the detailed explaination...

I have used the formula d= MP/RT recently for the Gas Problems...So it's still fresh in my memory

thank you again

Woops, 

Heh, got ahead of myself.  I was thinking of gases.  You are using water in its liquid form.  You can't use this equation with liquid water!

 

[pr33ti]

Using this renewed equation, we can see that density and temperature are indirectly proportional; as T increases, d decreases, as T decreases, d increases.

Use this equation!
               

most certainly I will.... thank you for the detailed explaination...

I have used the formula d= MP/RT recently for the Gas Problems...So it's still fresh in my memory

thank you again

Woops, 

Heh, got ahead of myself.  I was thinking of gases.  You are using water in its liquid form.  You can't use this equation with liquid water!

 

No worries... It's often more profitable to learn from mistakes...