Turn on thread page Beta
 You are Here: Home

# rate of reactions on a graph is straight line but adding water causes... why??? watch

1. rate of reaction/ order of reactions

if rate of the reaction on a concentraction-time graph is straight line and adding water causes the straight line to change to a curve on the concentraction-time graph? why????
2. when you add water, and you still use the same volume to do the same reaction, do you think the amount of your reactant(the mole quantity) is still the same?

Nope.

as concentration change when you add water(simple dilution)

i
3. (Original post by shengoc)
when you add water, and you still use the same volume to do the same reaction, do you think the amount of your reactant(the mole quantity) is still the same?

Nope.

as concentration change when you add water(simple dilution)

i
ahh okay, so the rate of reaction decreases because you have the same volume but due to addition of water, the concentration of the reactant deceases and thus the rate decreases and goes to curve shape.
4. (Original post by topboim)
ahh okay, so the rate of reaction decreases because you have the same volume but due to addition of water, the concentration of the reactant deceases and thus the rate decreases and goes to curve shape.
it is really the amount that reacts that matters, so if you use the same volume of reactant A(say conc = 1 M ) and reactant B(say conc = 0.1 M )

where A and B are the same solutions with different concentrations.

In 1 dm cube, mol of A = 1 mol and mol of B = 0.1 mol

If what A and B reacts with is to be present in excess, and also if A(or B) is present in the rate equation, then you can see that amount of A or B does affect the rate.

Turn on thread page Beta

### Related university courses

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: March 24, 2011
The home of Results and Clearing

### 2,107

people online now

### 1,567,000

students helped last year
Today on TSR

### University open days

1. Sheffield Hallam University
Tue, 21 Aug '18
2. Bournemouth University
Clearing Open Day Undergraduate
Wed, 22 Aug '18
3. University of Buckingham