Chemistry Forums for Students > Chemistry Olympiad and other competitions

Can someone tell me what I'm doing wrong here? (calculation)

(1/2) > >>

yuheng_wu:
Given:
- dioxide is being disolved in water.
- c=8mg/l
- Vwater=10,0 liters
- T = 25 °C = 298,15K
- p = 1013 hPa
The question is: 'how much volume dioxide kan disolve maximally in 10,0 liters of water at a temperature of 25°C and pressure of 1013hPa?
The answer is 61,1mL, however when I solve this problem my answer is 6,11mL. Could someone please tell me what I'm doing wrong?

mjc123:
First, O2 is dioxygen, not "dioxide".

You are using the concentration in mg/L, and working out the volume that dissolves in 1L. You are asked for the volume that can dissolve in 10L.

yuheng_wu:

--- Quote from: mjc123 on December 16, 2020, 03:00:40 PM ---First, O2 is dioxygen, not "dioxide".

You are using the concentration in mg/L, and working out the volume that dissolves in 1L. You are asked for the volume that can dissolve in 10L.

--- End quote ---
So c= ndissolved substance/Vsubstance here I can say that V substance = 10 liters? I though that this is incorrect since V substace is equal to Vwater+Vdioxygen = 10 liters + x liters or am I understanding this formula incorrectly? I do understand my mistake now but I don't understand this formula.

AWK:
Such a small amount of oxygen dissolved in water practically does not increase its volume.

You have calculated the volume of oxygen dissolved in 1 L of water in the longest possible way. How much oxygen will there be in 10 liters of water?

yuheng_wu:

--- Quote from: AWK on December 16, 2020, 04:13:25 PM ---Such a small amount of oxygen dissolved in water practically does not increase its volume.

You have calculated the volume of oxygen dissolved in 1 L of water in the longest possible way. How much oxygen will there be in 10 liters of water?

--- End quote ---
Ah yes the volume of oxygen would not really increase it's volume indeed, I understand. You said I have calculated the volume in a very inefficient way? How could I do this faster/more efficiently please?

Navigation

[0] Message Index

[#] Next page