Write the oxidation half reaction and reduction half reaction for the following: 1. Mg + H+ --> Mg^2+ + H2
2. Kl + Cl2 --> + I2
3. MnO4^1- + H^+ + Fe^2+ --> Mn^2+ + Fe^3+ + H2O
4. Crl3 + BrO3^- + OH^- --> CrO4^2- + Br^- + H2O + I2

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%

c-14 is carbon-14, or radiocarbon.   it is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons.