Sucrose (C12H22O11) is produced by plants as follows: 12 CO2(g) + 11 H2O(l) → C12H22O11 + 12 O2(g) H = 5645 kJ About 4.8 g of sucrose is produced per day per square meter of the earth's surface. The energy for this endothermic reaction is supplied by the sunlight. About 0.1 % of the sunlight that reaches the earth is used to produce sucrose. Calculate the total energy the sun supplies for each square meter of surface area. Give your answer in kilowatts per square meter 1kW/m2 where 1W = 1 J/s2.
Suppose an Olympic diver who weighs 52.0 kg executes a straight dive from a 10-m platform. At the apex of the dive, the diver is 10.8 m above the surface of the water. (a) What is the potential energy of the diver at the apex of the dive, relative to the surface of the water?


Verified Solution

Key Concepts
Potential Energy
Mass
Height in Gravitational Potential Energy
At 20 °C (approximately room temperature) the average velocity of N2 molecules in air is 1050 mph. (b) What is the kinetic energy (in J) of an N2 molecule moving at this speed?
Suppose an Olympic diver who weighs 52.0 kg executes a straight dive from a 10-m platform. At the apex of the dive, the diver is 10.8 m above the surface of the water. (b) Assuming that all the potential energy of the diver is converted into kinetic energy at the surface of the water, at what speed, in m>s, will the diver enter the water?
Consider the following unbalanced oxidation-reduction reactions in aqueous solution:
Ag+(aq) + Li(s) → Ag(s) + Li+(aq)
Fe(s) + Na+(aq) → Fe2+(aq) + Na(s)
K(s) + H2O(l) → KOH(aq) + H2(g)
(a) Balance second reaction.
Consider the following unbalanced oxidation-reduction reactions in aqueous solution:
Ag+(aq) + Li(s) → Ag(s) + Li+(aq)
Fe(s) + Na+(aq) → Fe2+(aq) + Na(s)
K(s) + H2O(l) → KOH(aq) + H2(g)
(a) Balance third reaction.