# Determining the glucose concentration in Sprite

**Topics:**Glucose, Concentration, Potassium permanganate

**Pages:**7 (954 words)

**Published:**February 3, 2015

Date: 23/1/2015

Partners: Sunniva & Bayu

Determining the concentration of glucose of 7UP

Glucose solutions prepared as follows:-

In each case 250.0 cm3 volumetric flasks used

Concentration (%)

Mass/g

4.00

10.00

8.00

20.00

12.0

30.00

16.0

40.00

20.0

50.00

Table: 1- Recording of concentration, volume, and qualitative observations of various solute/solvent/solution used during the experiment. Name

Concentration (%)

Volume (ml)

Qualitative Observations

Glucose (C6H12O6)

5 different types:

4%,8%,12%,16%,20%

5.0 ± 0.1 ml

Clear, Colourless

Name

Concentration (M)

Volume (ml)

Qualitative Observations

Potassium Permanganate (KMnO4)

0.010 M

1.00 ± 0.05 ml

Intensely pink/purple

Sulphuric Acid (H2SO4)

1 M

5.0 ± 0.1 ml

Clear, Colourless

Data Collection:-

Table: 2- Shows the concentration of glucose solution (%) and the total time taken (s) by the solution to decolorize

Glucose Solution (%)

Time (± 1 s)

Trial 1 (Me)

Time (± 1 s)

Trial 2 (Sunniva)

Time (± 1 s)

Trial 3 (Bayu)

4%

189

195

196

8%

129

211

135

12%

143

148

146

16%

160

175

162

20%

231

226

218

7UP

99

93

95

Data Processing:-

Table: 3- Shows the concentration of glucose solution (%) and the time after subtracting the lap time (s) took by the glucose solution to decolorize. Also the average for all three trials are calculated and shown below. Glucose Solution (%)

Time (± 1 s)

Trial 1 (Me)

Time (± 1 s)

Trial 2 (Sunniva)

Time (± 1 s)

Trial 3 (Bayu)

Average

4%

189

195

196

=(189+195+196)/3

=193

8%

99

181

105

=(99+181+105)/3

=128

12%

83

88

86

=(83+88+86)/3

=86

16%

70

85

72

=(70+85+72)/3

=76

20%

111

106

98

=(111+106+98)/3

=105

7UP

99

93

95

=(99+93+95)/3

=96

The following lap times were subtracted from respective Glucose Solution (%) For 8%- 30 second was subtracted

For 12%- 60 second was subtracted

For 16%- 90 second was subtracted

For 20%- 120 second was subtracted

Since we used a single stopwatch we had to subtract the lap times as explained above. Graph 1: Average Time VS Concentration of Glucose Solution (%) is graphed.

In terms to obtain a graph with the linear relationship, reciprocal of average time (1/s) and concentration of glucose solution (%) was graphed.

Table: 4- Reciprocal of average time (1/s) is calculated for each concentration of glucose solution (%). 7UP is not taken into consideration since we are finding the glucose concentration (%) for it.

Glucose Solution (%)

Average time (s)

Reciprocal of average time (1/s)

4%

193

=(1/193)

=0.00518

8%

128

=(1/128)

=0.00781

12%

86

=(1/86)

=0.0116

16%

76

=(1/76)

=0.0132

20%

105

=(1/105)

=0.00952

Graph 2: Reciprocal of average time (1/s) VS Concentration of Glucose Solution (%).

The equation obtained from the graph:

y = 0.0004x + 0.0053

y is reciprocal of average time

x is Concentration of Glucose Solution (%)

Reciprocal of average time (1/s) for 7UP:

= (1/96) = 0.0104

Since we are determining the concentration of glucose solution (%), we need to substitute the reciprocal average time which is 0.0104 into y and solve for x.

Below is a snapshot from http://www.7up.com/text/product/7up/nutritional-info/ which states the nutritional facts about 7UP.

Since,

240 ml = 25g (theoretical value)

We need to get the experimental value to calculate the percentage error. In order to do so, we must do the following:

12.75% glucose concentration (%) but we need to obtain a mass in terms to calculate the percentage error. So, 0.1275 X 250 cm3 = 32 g which is the mass of the glucose

The aim of the lab was to calculate the concentration of the glucose in 7UP and that was done in the following manner: Moles= Mass/Molar Mass of glucose (C6H12O6)

Moles= (32g)/ (180.18g/mol)

Moles= 0.18 moles

Now we can find the concentration using the formula below:

n=cv...

Cited: http://www.7up.com/text/product/7up/nutritional-info/

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