Answer:
mass of hydrogen in lake = 11.19% of 12
= 1.3428
check if question is correct or not
Explanation:
The oxidation half-reaction occurs at one electrode (the anode), and the reduction half-reaction occurs at the other (the cathode). When the circuit is closed, electrons flow from the anodeto the cathode.
One chemical change would be baking the muffin.
One physical change would be chopping the fruits to add to the mixture
1) Balanced chemical reaction: Cl₂ + 2NaI → 2NaCl + I₂.
Chlorine and iodine are diatomic molecules.
2) Balanced chemical reaction: 2NH₃ → N₂ + 3H₂.
Nitrogen and hydrogen are diatomic molecules.
3) Balanced chemical reaction: 4Na + O₂ → 2Na₂O.
Sodium in compounds has oxidation number +1 and oxygen -2.
We know 1 mole of any atom or molecules contains 
atom or molecules.
1 mole of HBr i.e 81 gm/mol contains atom or molecules.
So, mass of 
molecules is :
Therefore, mass of molecules is 1.21 gm .
Hence, this is the required solution.
