If the heat of formation of H2O(l) is –286 kJ/mol, which of the following thermochemical equations is correct?
(a) 2 H(g) + O(g) H2O(1)
AH = -286 kJ
(b) 2 H2(g) + O2(g) 2 H2O(1)
AH = -286 kJ
(c) H2(g) + 3 02(8) H2O(0
AH = -286 kJ
(d) H2(g) + O(g) →→ H2O(g)
AH = -286 kJ
(e) H2O(1) H2(g) + 2 02(8)
AH = -286 kJ
Practice Exercise 2

Firstly, the water in the dams hold gravitational potential energy as they are above ground level. the gravitational potential energy is then transferred to kinetic energy as it falls, spinning the turbinethe turbine then spins the generator, which is a large magnet surrounded by metal coils. by doing this, the generator generates electricity. in this action, the energy transfer taken place is kinetic to electric energy

You would be correct, boiling water does disinfect contamination.    the property of disinfecting means to kill  germs, bacteria and other pathogens or contamination  that might cause an infection or cause a person to become sickly. a couple methods of disinfecting are using soap, other cleaning supplies or by simply "boiling" the contaminate.  the reason why boiling water disinfects certain attributes is because some cells cannot survive the heat and pressure.