Consider this reaction:
2H3PO4(aq)→ P2O5(aq)+ 3H2O

At a certain temperature it obeys this rate law. rate
rate= (46.6M^-1. s^-1) [H3PO4]^2

Suppose a vessel contains H3PO4 at a concentration of 0.660M. Calculate how long it takes for the concentration of H3PO$ to decrease to 20% to its natural value. You may assume no other reaction is important. Round your answer to significant digits.

  0.0345 sec

Explanation:

Rate law says that rate of a reaction is directly proportional to the concentration of the reactants each raised to a stoichiometric coefficient determined experimentally called as order.

k= rate constant =

Expression for rate law for first order kinetics is given by:

where,

k = rate constant

t = age of sample

a = let initial amount of the reactant

a - x = amount left after decay process  

for completion of 20 % of reaction

The time taken for the concentration of to decrease to 20% to its natural value is 0.0345 sec

- both b and d.

-since b and d are the closest coastlines then that makes it the most affected.

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on passing the small ampere of electric current through the tube made of ar and hg of cfl generates uv rays which excites the fluorescent and thus emits the high radiation by consumption of just 5- 12 w in comparison to incandescent light which requires more power such as around 40 - 55 w to lighten.

moreover the life span of fluorescent or cfl is around 8000 h whereas the life span of incandescent is around 1200 h

hence, the building installed with incandescent lights bears more electricity bill.