Why is the energy supplied by the cooker greater than that calculated in part (a)

136000 J or 136 kJ

Explanation:

Formula

Heat = m * c * deltaH

Givens

m= 0.5 kg

c = 3400 J / (kg * oC)

Deltat = (100oC – 20oC)

deltat = 80oC

Solution

Heat = 0.5 kg * 3400 J/(kg* oC) * 80oC

Heat = 136000 Joules

Heat = 136 kg

Technically there is only 1 place of accuracy.

when [oh-] is 10-5  m, and [h3o+] is 10-9  m, the poh is 5 and ph is 9. again in both cases the sum of ph and poh is 14. however, the hydrogen ion concentration is not always going to be equal to exactly 1 x 10 raised to a negative number. for example, we skipped over the value of 2.0 x 10-7.