Chemistry questions I

[Awuah29]

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A flask weights 95g when empty. when filled with 200 ml of a certain liquid, the weight is 328g . What colume (in milliliters) would 100g of the liqid occupy?

Anyone know what formula to use?


If a solution is 0.50M in a cpd X
decomposes for 5.0 minutes at the average rate of 0.040 mol?L. min the new concentration of X will be ?

What formula do I use here?

By the way these questions come from the tutorial material
thanks guys

 

[drpduck]

If a solution is 0.50M in a cpd X
decomposes for 5.0 minutes at the average rate of 0.040 mol?L. min the new concentration of X will be ?

For this I would just do 0.040M/min x 5.0 min= 0.200 M, the amount that decomposed in 5 mins

The final concentration is: 0.50M-0.20M= 0.30M

Perhaps this is too simple to be correct but it is the way I would approach it.

 

[coodoo]

A flask weights 95g when empty. when filled with 200 ml of a certain liquid, the weight is 328g . What colume (in milliliters) would 100g of the liqid occupy?

Anyone know what formula to use?

the mass of the liquid in the container is 328-95 = 233g...

now find the density of the liquid which is d = m/v = 233/200 or 2.33 g/ml

so now 2.33 g/ml = 100/V or V = 100/2.33 = 43 ml

 

[Awuah29]

I was basically looking for specific formulas for to those two problems.
Anyway thanks

 

[boogaking]

On that explanation .... can you tell me how you got 2.33??? 233/200= 1.165 right???

please explain... if you have time =)