Concentration of Sodium Chloride Ions in a Solution 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 ======= Using different equipment Using the same equipment Concentration (m) Current (A) Current (A) 0.5 0.44 1.92 1 1.93 1.73 1.5 1.98 2.07 2 2.22 2.41 2.5 1.16 2.55 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
taken into account. It is also best to make sure you are working in a
For my derivative project I chose to graph Emmitt Smith’s annual rushing yard total. Emmitt was drafted out of University Florida in 1990 and began his career as an NFL Great. As you can see on the graph, Smith began his career slowly, amassing only 937 rushing yards his rookie year. However, his second year Smith improved to 1563 rushing yards. In his third season, Smith again improved to 1713 rushing yards. The decrease in production Smith’s fourth and fifth year (1486 and 1494 respectively) in the NFL can be partially credited to the fact Smith did not compete in all sixteen regular season games due to injuries. Smith redeemed himself the following year with a career high 1773 rushing yards. Over the next six years Smith’s age slowly caught up to him as he ranged from 1021 to 1397 yards. Finally, after his thirteenth year as a Dallas Cowboy, Smith was traded to the Arizona Cardinals. In his first year with the Arizona Cardinals (2003), Smith was injured and played as a backup for the majority of the year. This is illustrated through his career low 256 rushing yards. However, in Smith’s final year in the NFL, he rushed for 937 rushing yards, bouncing back from a disappointing year. Strangely, Smith ended his last season with the same rushing total as his rookie season. I plotted these points in a graph in an excel document and created a line of best fit. This line was a cubic equation (f(x) = 1.4228x3 - 8533.3x2 + 2E+07x - 1E+10).
I expect my graph to look like it does on the next page because I
because of the line of best fit. Using line of best fit means I can
Above is my original data. In the graph, it can be seen that there are
The experimental data suggest that calcium chloride (CaCl2) is the best salt to include in a hot pack because it was the most exothermic out of the tested salts. The average heat of reaction (q_(rxn,p)) of CaCl2 was calculated to be -460J. Additionally, the low cost of CaCl2 makes it an ideal choice for the widespread use of hot packs. Although the value for MgSO4 (average qrxn -443), the cost is over six times higher. Another issue to consider is the safety and toxicity of the product. According to the PubChem Open Chemistry Database calcium chloride can cause cough, sore throat and a burning sensation when inhaled (1). It can also cause redness, dry skin, and skin burns when it comes into contact with the skin. If ingested, CaCl2 can cause
The Effect of the Amount of Sodium Chloride on the Electric Current During Electrolysis Background When an electric current passes through sodium chloride solution, chemical reactions take place at both cathode and anode. If one passes through sodium chloride solution, there will be passage of ions moving through this solution. This results in positively charged sodium ions, which have been dissolved into the solution, moving towards the cathode and deposited there. At the same time, negatively charged chloride ions will be moving towards the anode and discharged at the anode. This is called electrolysis.
Below the graph consist of the intersections of the line ‘y = x’ , ‘y = 2x’ with the curve y = x4
Electrical conductivity refers to a substances ability to carry moving electrons (conduct electricity). In order to do so, there must be a supply of delocalised electrons. While in a solid state, ionic substances can not conduct electricity as there are no delocalised electrons or free/mobile ions to act as charge carriers. In an aqueous ionic solution, the H2O molecules break apart the crystal lattice structure of the ionic substance into individual ions, surrounding each ion in a jacket of hydration. Below is the equation that describes the dissociation of NaCl when in H2O solvent.
from 10cm to 50cm to make it easier to see the difference in a graph.
the left so that the concentration of H is more than Me and so the
The Solubility of Potassium Nitrate Aim To investigate how the solubility of Potassium Nitrate is affected by Temperature. Background Knowledge Potassium Nitrate (KNO3) is an ionic compound. The strong ionic bonds hold the compound in an ionic lattice which gives KNO3 its crystalline structure. These ionic bonds also have other properties which will affect my investigation, I must be aware of these properties for greater accuracy in my method.
This graph shows the result that I expect to get, I expect to see a
From the graphs, it could be determined that the results are fairly precise due to the data points being fairly close rather than scattered. This can be seen as all the points are relatively close to the average value on graphs 1 and 2, not causing the trend line to be skewed.
6. I then rinsed out the beaker and glass rod into the flask to make