extention english could be given like half the marks, and then the half of another of your 2 unit courses would be included with it. but seriously. backto the chem i say.
well, i assume this is from Shipwrecks and Salvage? the ones you've listed sound like the best from my uneducated-in-the-ways-of-the-module brain. unless you want to use stuff like titanium or gold :). Anything that doesn't react with either water or salt should work i would think.
i dont think they would, but if they did, you could draw the little activation energy ciagram, drawing two liens, with one being lower at its apex to imply the use of a catalyst.