Extracts from this document...

Introduction

Salters as Practical Assessment-Plan I am going to plan an experiment to determine the accurate concentration of sulphuric acid. It is thought to have the concentration between 0.05 and 0.15 moldm-3. I will be provided with a solid base which is anhydrous (powder) sodium carbonate (Na2CO3). To find the accurate concentration I will titrate the sulphuric acid against the sodium carbonate. The reaction following will take place: Na2CO3 (aq) + H2SO4 (aq) Na 2 SO4 (aq) + CO2 (g) + H2O(l)1 Deciding the Amounts Sulphuric acid has a concentration about 0.10 moldm-3 (half way between 0.05 and 0.15 moldm-3). I would like to use 25cm3 of sulphuric acid. This is because, it is not a wasteful amount and also it would reduce percentage errors because this is quite a large amount to use. It would be an ideal value to use. Furthermore, I will need to make up a standard solution from the solid base that I have been provided with, which is sodium carbonate. I would again ideally like to use 25cm3 of the standard solution per titre. This is because, the pipettes have the reading of 25cm3, which means the pipette is readily, available for this amount, therefore it is a sensible value. ...read more.

Middle

Wear safety goggles, gloves and also protective clothing. If in contact with eyes wash quickly with clean water. If spilt on skin wash intensely. If inhaled move to an area of fresh air. If spilt anywhere scoop as much as possible up. 5 Methyl Orange Indicator 2-3 drops Irritant Wear safety goggles, gloves and also protective clothing. If spilt, clean it up using a cloth and water. If gets in contact with skin wash the area thoroughly. If enters eyes wash with clean water. 6 Why my plan will Devise Reliable results My plan will devise reliable result because of many reasons. Firstly I am going to do a rough titre in my plan, which means I will have a rough idea of my titration, so when I do my real results I know when to add it drop wise, so that I won't overshoot the end point. Another reason why I won't overshoot the end point is because I am going to use a white tile so I can judge the end point more accurately. Furthermore, I am only going to add 2 or 3 drops of methyl orange indicator. This will make my results more reliable because the methyl orange indicator is slightly acidic, so it would use up the alkaline solution, therefore by only adding a small amount of it will make my results more reliable and accurate. ...read more.

Conclusion

Therefore, I used 0.0253 moles in my standard solution. I now need to use the equation to find the concentration: Concentration (moldm-3) = Number of moles/Volume (dm3) I firstly need to convert 250cm3 to dm3 so that my equation works: 1000cm3 = 1dm3 250cm3 = 0.250dm3 (I divided by 1000). Concentration (moldm-3) = 0.0253moles/0.250dm3 Concentration= 0.101moldm-3 Consequently, I have calculated my sodium carbonate standard solution to have a concentration of 0.101moldm-3, rounded to three significant figures. Concentration of acid I am now going to calculate the concentration of the acid solution; therefore I firstly need to find out how many moles there is of the sodium carbonate solution, by using the equation: Concentration of Na2CO3 (moldm-3) x Volume of Na2CO3(dm3) = Number of moles of Na2CO3 0.101moldm-3 x (25/1000) dm3) =0.00253 moles The equation of my reaction is: Na2CO3 (aq) + H2SO4 (aq) Na2SO4 (aq) + CO2 (g) + H2O(l) This equation shows that the molar ratio of sodium carbonate and sulphuric acid is 1:1 which means is there is 0.00253 moles of sodium carbonate there is 0.00253 moles in sulphuric acid. The average titre as shown above was 20.075cm3, which I need to convert to dm3 which is: 20.075cm3/1000 = 0.0201dm3. I can now use the equation Concentration (moldm-3)= Number of moles/Volume (dm3) Concentration (moldm-3)= 0.0253 / 0.0201 Concentration = 0.126moldm-3. Overall, I conclude that the concentration of the acid solution is 0.126moldm-3. ...read more.

This student written piece of work is one of many that can be found in our AS and A Level Physical Chemistry section.