Consider this reaction:
2H3PO4(aq) –> P2O5(aq) + 3H2O(aq)
At a certain temperature it obeys this rate law.
rate = (16.9 M^-1 .S^-1)[H3PO4]^2
Suppose a vessel contains H3PO4 at a concentration of 0.770 M. Calculate how long it takes for the concentration of H3PO4 to decrease by
90.0%. You may assume no other reaction is important.
Round your answer to 2 significant digits.

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)

answer: the primary difference between a hypothesis and a theory is that b hypothesis is falsifiable, but a theory has been proven to be correct. theory is an explanation of something that is happening but hypothesis is a guess of something that can happen

explanation:

shield volcanos are angry and get mad over the smallest things so much that there heads erupt   pahoehoe and a'a lava. a composite volcano is the poller opposite of a shield volcano. its   peaceful thing and knows how to control its emotions.      

the cold front replaces the warmer air at the ground level changing the wind to be breezy and denser.there is also an immediate drop in the temperature.