• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month
Page
1. 1
1
2. 2
2
3. 3
3
4. 4
4
5. 5
5

# Using Redox Titration to Analyze the Oxidizing Strength of Bleach Lab

Extracts from this document...

Introduction

Abhinav Jain Ms. O'Hanlon Chemistry HL Period 8 22nd November, 2009 Using Redox Titration to Analyze the Oxidizing Strength of Bleach Lab Data Collection and Processing: Volume of KIO3 = 10.00 cm3 = 0.01 dm3 Molarity of KIO3 = 0.005000 M Since M = n/v Moles of KIO3 = 0.01 dm3 � 0.005 m = 0.00005 moles KIO3 The following table shows values for standardization: (Trial) Titration 1 � 0.05 cm3 Titration 2 � 0.05 cm3 Titration 3 � 0.05 cm3 Start 0.00 15.50 30.70 End 15.50 30.70 46.00 Total 15.50 15.20 15.30 Average Titre value= (15.20 + 15.30)/2 = 15.25 cm3 = 0.01525 dm3 Uncertainty Propagation found later Qualitative Observations: The Sodium Thiosulfate was white and clumped up into rocks. When mixed with water, it dissolved easily. The Sodium Carbonate was white and very fine like iron filings and again, dissolved easily when mixed with water. In order to find the concentration of the Thiosulfate, we need to convert the moles of KIO3 into moles of S203 Looking at the following equations: IO3- (aq) + 5 I- (aq) + 6 H+ (aq) ...read more.

Middle

2 S203 2- (aq) + I2 (aq) 2 I- (aq) + S406 2- (aq) ClO- + 2I- + 2H+ H2O + I2 + Cl- The Hypochlorite to Iodine ratio is 1:1 And the Thiosulfate ratio to Iodine is 2:1 Therefore the Thiosulfate to Hypochlorite ratio is 2:1 Therefore, Hypochlorite moles = Thiosulfate moles/2 = 0.000403279 moles/2 = 0.000201639 moles Since there was a dilution of 1 to 10, the moles above need to be multiplied by 10 = 0.000201639 moles � 10 = 0.00201639 moles In order find the % by mass of the Hypochlorite, one needs to multiply the moles by (Molar mass of NaClO/mass average (Experimental) = 0.00201639 moles � (74.5/3.01) = 0.04990741245 � 100 = 4.990741245% Uncertainty Propagation: Uncertainty from massing scale = 0.02/3.01�100 = 0.66% Uncertainty from Volumetric Pipette = 0.04/25�100 = 0.16% Uncertainty from titration 1(Burette) = 0.05/15.25�100 = 0.33% Uncertainty from titration 2(Burette) = 0.05/20.05�100 = 0.25% Once of all of them have been added up, = 0.66 + 0.16 + 0.33 + 0.25 = 1.4% For relative uncertainty, 1.4% of 4.990741245% = 0.06987037743 % Conclusion and Evaluation: The experimental value obtained for the % by mass of the NaClO which is the oxidizing agent is 4.99%. ...read more.

Conclusion

This is because after the sodium Thiosulfate pentahydrate was poured down from the weighing boat, some visible particles could still be seen on the boat. Since more mass was measured then the actual mass used, this will mean our molar mass value will be high as our mass value will be too high. In order to improve this error, the acidic salt remaining on the weighing boat should have been washed down with distilled water giving us more accuracy. Instrumental Error It was assumed that all the hypochlorite was NaClO3 when in fact it could have included other impurities. This would have affected our final value because if we took into account a larger mass, that means our mass value would have been too high causing our percentage value to be low which was the case in this lab. A way to improve this would be to find out what other compounds were present in that bleach so that those values can be taken into account for. An overall improvement method to reduce random errors in this lab would be repetition of trials. Overall, this experiment was fairly accurate and precise resulting in not many errors overall. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate Chemistry section.

## Found what you're looking for?

• Start learning 29% faster today
• 150,000+ documents available
• Just £6.99 a month

Not the one? Search for your essay title...
• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month

# Related International Baccalaureate Chemistry essays

1. ## Aim: To find the molar mass of butane, by finding the number of moles ...

This is also shown by the fact that the y-intercept is 0.0125, which is very close to 0, showing an almost completely proportional relationship between mass and n.

2. ## Thermometric titration lab

Time (seconds) Calculation of average Average Temperature (�C) Sample calculation 0 � 0.1cm3 0 � 0.5s (22.5 +22.5)�2 22.5 � 0.1 2.0 � 0.1cm3 20 � 0.5s (24.1 +24.5)�2 24.3 � 0.1 4.0 � 0.1cm3 40 � 0.5s (26.4 +25.7)�2 26.1 � 0.1 6.0 � 0.1cm3 60 � 0.5s (26.7

1. ## Energetics Design Lab

?H (neutralization) = 0.22/0.017 = -13.0 kJ/mol % Error ((-13 - -54.9)/-54.9 ) x 100% = 76.3% Percentage Uncertainty: Hydrochloric Acid: Scale: (0.005/2.65) x 100% = 0.189% Delta Temperature: (0.5/3.3) x 100% = 15.2% q = %unc(m) %unc(T) = 15.4% M(acid) = (0.005/1.00)

2. ## alkali titration

* When about 20.3dm3 of the acid was added, the pink solution turned completely clear. Data Processing 1. Write an equation for the reaction. (COOH)2 + 2NaOH --> 2NaCO3 + 2H2O 2. What amount (in moles) of NaOH is present in 20.0 cm3 of 0.097 mol dm-3 sodium hydroxide solution?

1. ## chem design lab 2

After doing 2 minute trial, then Measure about 20 ml of water with the graduated cylinder for 3 minute trial. 19. measure the temperature of the water and record it under 3 minute trial 20. Place the liquid fuel under the beaker and carefully light the candle 21.

2. ## Chemistry Titration Acid Base Lab

Therefore, there was lot of time before the water was placed in the volumetric flask for the sodium hydroxide pellets to absorb moisture from the air. This is a concern as solid sodium hydroxide has the formula NaOH (s). Additionally in air there is carbon dioxide (CO2).

1. ## Investigating the strength of Electrolytic solutions

setting of 300mA, is 5 amp per reading but if measured at 0.3mA, it is read as 0.005 amp per reading. 2.1. Data Processing 2.1.1. Average and standard deviation of current in mA following through different electrolytic solutions Table 2 Types of Trial 1 Trial 2 Trial 3 Unit and Multimeter Average Standard Acid or Base?

2. ## Objective: To investigate the order of oxidizing ability of the halogens Cl2, Br2, and ...

Cl2 is more reactive and oxidising agent I2 present and Br2 is oxidizing agent 2. Colour after shaking with KBr solution colourless X Dark red Colour of each layer after shaking with hexane upper colourless X Purple lower colourless X light red Conclusion Br2 present and Cl2 is the stronger oxidizing agent X No visible reaction observed 3.

• Over 160,000 pieces
of student written work
• Annotated by
experienced teachers
• Ideas and feedback to
improve your own work