Answer:
7430.5 Joules (7.4*10^4 Joules)
Explanation:
Q=mc∆T
where Q is energy in Joules.
Now m=250 g
c= 0.386 J/g°C
∆T = 99 - 22 = 77 °C
plugging the values in gives
Q=250*0.386*77=7430.5 Joules
(7.4*10^4 Joules, if 2 significant figures)
Molar mass SiO2 = 28 + 32 = 60
<span>so moles sand = 3.4 x 10-7 / 60</span>
electrons are transferred in a oxidation-reduction reaction
oxidation reduction chemical equation involve electrons transfer between two species. In this reduction-oxidation type of chemical equation oxidation number of molecule, atoms or ion changes by gaining or losing electrons,that is there an oxidizing agent and a reducing agent in the reaction.
<span>Petroleum and biomass are burned in combustion reactions, which liberate energy stored in chemical bonds. This is chemical energy. In contrast, nuclear energy comes from the conversion of mass into energy when an nuclear reaction occurs. Geothermal energy comes directly from heat sources underground, with no chemical or nuclear reactions.</span>
