Chlorine (Cl2Cl2) is a strong germicide used to disinfect drinking water and to kill microbes in swimming pools. If the product is Cl−Cl−, was the elemental chlorine oxidized or reduced?

The elemental chlorine was reduced

Explanation: inl the elemental form, the oxidation state of chlorine is =0 on been reduced to Cl-Cl-, the oxidation state reduces to -1

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.