# If I double the concentration of Sodium Chloride ions in a solution the current that can flow through the circuit will also double.

Vicki Speak

Chemistry Coursework

Prediction

If I double the concentration of Sodium Chloride ions in a solution the current that can flow through the circuit will also double.

Controlled Variables

• Temperature: Room temperature-15ºc
• Voltage: 6V
• Volume of water: 200cm³
• Equipment: see diagram

## Diagram

How to make the concentration

• 0.5M = 5.85g in 200cm³
• 1M = 17g in 200cm³
• 1.5M = 22.85g in 200cm³
• 2M = 34g in 200cm³
• 2.5M = 39.85g in 200cm³

## Method

• Set up all the equipment
• Switch on the circuit
• Write down the first current seen
• Switch the circuit off.

## Results

Analysis

I found out that the results follow a trend.  The trend is that the points on the graph are in a straight line, which curves off towards the top right hand corner of the graph.  The last point on my graph was lower than I expected, which is why the line curves off towards the end of the graph.  I also found out that as the concentration gets higher, so does the current.

I have drawn two lines of best fit on my graph, because the first line I drew didn’t go through all the points but it did go through (0,0) whereas the second line went straight through three points, which were points two, three and four.  The reason that the first line of best fit did not go through any points is that I would have expected points one, two, four and five to have been lower on my graph.

## The Prediction

I predicted that if I double the concentration of Sodium Chloride ions in a solution ...