On Tue, 29 Mar 2011 09:01:13 -0700, "bob" wrote:

Years ago I bought a bottle of sulfuric acid from a hardware store with the
intend to open a clogged pipe. I ended up opening the clog with another
method. The bottle sits unused.

Many toilet bowl cleaners use hydrochloric acid as a main ingredient, since
sulfuric acid is similar stuff, can I use it as a toilet bowl cleaner?

absolutely NO!!!

the concentration is unknown. pouring acid into water can lead to a
raid dissociation reaction which can throw all kinds of stuff back in
your face. AND the residue left behind...even a few drops...will be
VERY dangerous.

i'm an MS chemist. i use H2SO4 routinely in my work. you do NOT want
to do this. H2SO4 has some great properties when used in certain
applications but it should NEVER be used for THIS applicatiion!