calibration curves

Question 1

benedict’s reagant is referred to as ______ quantitative - why?
what exactly is giving benedict’s that blue colour?
reducing sugars such as glucose ______ electrons
what would it mean if the benedict’s reagant wasn’t that strong of a blue?
what would’ve happened to these cu2+ ions?
the more glucose there is….. (2 things)
the______ conc of glucose the _____ blue benedict’s will be
why is benedicts reagant blue?
what colour does benedicts absorb the best?
note: this is bc it’s on the opposite spectrum to blue
note: we’d say red is complementary to blue
if our benedicts isnt that blue how much red light will be absorbed?
carrying on from this, since most of it won’t be absorbed it’ll be…
_____ red light absorbed, the _____ the amount of glucose that must’ve reacted with the benedicts

Answer 1

• semi quantitative as it gives you an approximate idea on the level of reducing sugar there is
• cu2+ ions
• donate electrons
• not much cu2+ ions
• either reacted or no longer in the solution
• the less blue benedicts is and fewer cu2+ ions in the solution
• greater, less
• if you shine white light through benedict’s solution all of the colours will be absorbed apart from blue which will just pass through
• red
• very little
• transmitted
• less, greater

Question 2

how to produce calibration curve:
- prepare range of known glucose concs
- react each of solutions w benedicts (HEAT AND MIX)
- filter off red precipitate
- colorimeter to see how much red lights been absorbed
- do the same but w unknown solution
-compare unknown solution and known solution
- find out conc of glucose in UNKNOWN solution

what is the name of our known conc?
what do you do if the absorbance of the unknown sample is too great to read off the calibration curve?

Answer 2

• ya Allah pls A*
• stock conc
• dilute solution and read absorbance again

Question 3

the ________ the absorbance, the ____________ the sugar conc
AND WHAT SUGAR IS IT?
the ____________ the transmission, the _____________ the sugar conc

variables of benedict’s reagant test:
what’s another thing you can do to make the benedicts reagant quantitative - basically something else alternatively
(PLUG IN)

Answer 3

• higher, higher - REDUCING SUGAR
• higher, lower
• volume of benedicts
• conc of benedicts
• the volume of sample
• temp its being heated at
• how long its being heated for
• filter and dry the red precipitate
• measure the mass of the red precipitate
• the more of the red precipitate the more of the reducing sugar