Xylene is a derivative of benzene. One isomer is 1,4-dimethylbenzene. H3C CH3 (a) State the number of 1H NMR signals for this isomer of xylene and the ratio in which they appear.

in theory, limestone is composed principally of the compound calcium carbonate - caco3, but in reality this compound is deposited in conditions involving a number of other compounds as impurities so it ends up being a mixture of many compounds.

hope this : -)

tony (lordcaos066)

catya your not at all which answer i've seen you do this on another question!

i think is conclusions.i think so