Photosysthesis si a bio process by which plants make energy rich molecules from low energy molecules with the help of energy from sunlight . The photosysthesis of glucose can be represented as:
`6CO_(2(g))+ 6H_(2)O_(g) + hv rarr C_(5)H_(12)O_(6(s)) + 6O_(2)(g)..........(i)`
The energy of one mole of a photon of wave lenght is known as one Einstein.
Heats of combustion of graphite and hydrogen at 298K are `-393.5 KJ"mol"^(-1)` and `-285.8 KJ"mol"^(-1)` respectively. If on combustion 1 g of glucose releases 15.58 KJ of energy , Calcualate the heat of formation of glucose at 298 K.

Answer

`C_(6)H_(12)O_(6) + 6O_(2) rarr 6CO_(2) + 6H_(2)O DH =-15.58 xx 2804.4 J`
`DeltaH=(H_(f))_(p)-(H_(f))_(R)`
`-2804.4 = (6 xx -393.5)+ (6 xx - 285.8) -(H_(f))_("Glucose")`
`therefore (H_(f))_("Glucose") =- 1271.4 KJ`
Diabetic patients have to monitor their blood glucose level periodically . Home glucometer is an appliance used for this purpose . This device consists fo a disposable test strip with carbon working electrodes and a reference electrode. The working electrode is converted with the enzyme glucose oxidise , which catalyses the reaction the glucose with dissloved oxygen.