#7 Could not be more wrong, which is no surprise from WD. I was top of my class in Chemistry. Obviously you were not.
Read the link, you might get a clue, possibly.
"simple chemistry: carbon dioxide dissolves in water. It reacts with seawater, creating carbonic acid."
"As we burn fossil fuels and atmospheric carbon dioxide levels go up, the ocean absorbs more carbon dioxide to stay in balance. But this absorption has a price: these reactions lower the water's pH, meaning it's more acidic. "