# Determining the glucose concentration in Sprite

Topics: Glucose, Concentration, Potassium permanganate Pages: 7 (954 words) Published: February 3, 2015
﻿Name: Raj Bose
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/