Mass of vitamin C (ascorbic acid) used to prepare stock soution 0.109g
Total volume of vitamin C stock soution 150.00ml
Volume of vitamin C (ascorbic acid) stock soution used for titration 8.0ml
Initial Iodine buret reating titration 0.10ml
Final iodine buret reading 37.62ml
Was this titration overshot?
Volume of Vitamic C stock solution used for titration 2 8.1ml
Initial iodine buret reading Titration 2 0.22ml
Titration of beverage of choice ]
Description of bevergae choice: lemon perfect pineapple coconut
serving size: 1 bottle 355ml
amount of Vitamic C per serving 90mg
volume of sample of beverage titration 1: 49ml
initial iodine buret reading titration 1: 7.09ml
final iodine buret reading titratin 1: 7.79ml
volume of sample of beverage titration 2: 50.0ml
Initial iodine buret reading titration 2: 7.79ml
Final iodine buret reading titration 2: 8.45ml
Calculated Quantities and Results, Standardization
# mg per mL of Vitamin C (ascorbic acid) in prepared stock solution:
Titration 1
Titration 2
Titration 3
Mass of ascorbic acid used (mg)
Moles of ascorbic acid used
Moles I2 used
Volume of I2(aq) (titrant) used (mL)
Molarity of I2 in titrant solution
Average molarity of I2 in titrant solution
Calculated Quantities/Results, Beverage Samples
Titration 1
Titration 2
Titration 3
Volume of I2(aq) (titrant) used (mL)
Moles I2 used
Moles of ascorbic acid in sample
Mass of ascorbic acid in sample (mg)
Mass of ascorbic acid per mL of sample (mg/mL)
Average Mass of ascorbic acid per mL of sample (mg/mL)
Analysis
1. What beverage(s) did you analyze? Write down here the serving size (in mL) and the amount of Vitamin C per
serving (in mg) from the label.
[NOTE: If the amount of Vitamin C per serving is stated only as a percentage daily allowance (DA), contact your instructor for guidance (you may
need to look up on the web the current value of DA for Vitamin C in the USA)]
2. Using the average value that you determined for the number of mg of Vitamin C per mL of beverage (calculated
from your raw data), along with the volume of one serving size of your beverage (as noted in #1, from the label), calculate
the (experimental) mg of Vitamin C in one serving size of your beverage. How well does your experimental value
agree with the value found on the label? Comment on potential sources of error in the experiment.
3. Comment on the precision of your determinations of both (a) the molarity of the iodine solution (titrant) and (b) the
mg of Vitamin C per mL of beverage. State clearly what you are looking at to assess this.
4. (a) To better quantify the precision comparison noted in #3 above, assume that a rough approximation of the %
uncertainty in each of the determinations can be calculated as follows: First, calculate the range of values (for
both the molarity and the mg/mL quantities) and divide it by 2 (i.e., take the largest value you got in one of your
trials minus the smallest value and divide the result by 2). Then, take that result (for each quantity—molarity and
mg/mL), divide it by the average value of that quantity (calculated on the previous page), and multiply by 100.
Setups/Calcs for % Uncertainty of Molarity of I2
Setups/Calcs for % Uncertainty of mg/mL of Vitamin C in beverage
(b) Based on this measure, which determination was more precise, the molarity of the iodine solution or the mg of
Vitamin C per mL of beverage?
This can be calculated using the following formula: Moles = Mass/Molar Mass. In this case, 0.109 g of ascorbic acid were used with a molar mass of 176.123 g/mol which leaves us with 0.0006169 moles.
We now need to convert these moles into volume by multiplying them by Avogadro’s number (6.02 x 10^23). This gives us 3.7457 x 10^20 molecules per liter or 374570 molecules per milliliter of ascorbic acid.
Next ,we must calculate how much iodine was needed to react with 8 ml of ascorbic acid . Since 1 mole(Avagadro’s number) reacts with 1 mole (Avagadro’s number)of iodine hence 8ml will require 8mole Iodine . As each ml contains 374570molecules 375×10^4ml iodine would be required for reaction
Now we can compare this figure with what actually happened; according our readings an additional 2762 ml were added which is significantly more than required for complete reaction thus indicating that titration has been overshot. In conclusion , from data gathered through calculations mentioned above it appears that this particular titration has indeed been overshot . However further investigations may carried out order ascertain if any errors occurred during experiment and if there are any ways reduce excess usage reagents future experiments
Transient memory is the memory for a boost that goes on for a brief time (Carlson, 2001). In reasonable terms visual transient memory is frequently utilized for a relative reason when one can’t thoroughly search in two spots immediately however wish to look at least two prospects. Tuholski and partners allude to momentary memory similar to the attendant handling and stockpiling of data (Tuholski, Engle, and Baylis, 2001).
They additionally feature the way that mental capacity can frequently be antagonistically impacted by working memory limit. It means quite a bit to be sure about the typical limit of momentary memory as, without a legitimate comprehension of the flawless cerebrum’s working it is challenging to evaluate whether an individual has a shortage in capacity (Parkin, 1996).
This survey frames George Miller’s verifiable perspective on transient memory limit and how it tends to be impacted, prior to bringing the examination state-of-the-art and outlining a determination of approaches to estimating momentary memory limit. The verifiable perspective on momentary memory limit
Length of outright judgment
The range of outright judgment is characterized as the breaking point to the precision with which one can distinguish the greatness of a unidimensional boost variable (Miller, 1956), with this cutoff or length generally being around 7 + 2. Mill operator refers to Hayes memory length try as proof for his restricting range. In this members needed to review data read resoundingly to them and results obviously showed that there was a typical maximum restriction of 9 when double things were utilized.
This was regardless of the consistent data speculation, which has proposed that the range ought to be long if each introduced thing contained little data (Miller, 1956). The end from Hayes and Pollack’s tests (see figure 1) was that how much data sent expansions in a straight design alongside how much data per unit input (Miller, 1956). Figure 1. Estimations of memory for data wellsprings of various sorts and bit remainders, contrasted with anticipated results for steady data. Results from Hayes (left) and Pollack (right) refered to by (Miller, 1956)
Pieces and lumps
Mill operator alludes to a ‘digit’ of data as need might have arisen ‘to settle on a choice between two similarly probable other options’. In this manner a basic either or choice requires the slightest bit of data; with more expected for additional complicated choices, along a twofold pathway (Miller, 1956). Decimal digits are worth 3.3 pieces each, implying that a 7-digit telephone number (what is handily recollected) would include 23 pieces of data. Anyway an evident inconsistency to this is the way that, assuming an English word is worth around 10 pieces and just 23 pieces could be recollected then just 2-3 words could be recalled at any one time, clearly mistaken. The restricting range can all the more likely be figured out concerning the absorption of pieces