Math Is Fun Forum

Janiffer

Member

Registered: 2008-04-26

Posts: 12

Differential equations

A nitric acid solution flows at a constant rate of 6 litres/ min into a tank which initially held 200 litres of 0.5% nitric acid solution. The solution in the tank is kept well mixed through stirring and flows out of the tank at a rate of 8 litres / min. If the solution entering the tank is 20% nitric, then

a) determine the volume of nitric acid in the tank after t minutes.

b) determine when the % of nitric acid reaches 10%.:|

John E. Franklin

Member

Registered: 2005-08-29

Posts: 3,588

Re: Differential equations

Can you guarantee there will be no chemical reaction
taking place?  Is the other component simply water?
If so,
Veverything = 200 + 6 t - 8 t.
   = 200 - 2 t
At t = 100 minutes, the tank is empty.

problem not finished...

---

igloo myrtilles fourmis

Dragonshade

Member

Registered: 2008-01-16

Posts: 147

Re: Differential equations

The vol of nitric acid at the beginning is 200x0.5%=1
The rate of flow in nitric acid is constant 6x20%=6/5
The escaping rate of nitric acid should be  v=8x(temp density of nitric acid) = 8x (amount of acid)/(total volume)

The speed of the change of volume of Nitric acid
Total volume = 200-2t 

   
At least thats what I think\

To question 2:

Density = V/(total volume)

Last edited by Dragonshade (2008-05-25 17:36:46)

Janiffer

Member

Registered: 2008-04-26

Posts: 12

Re: Differential equations

Thanks A Lot:))