The gas phase decomposition of nitrogen dioxide at 383 °C NO2(g)NO(g) + ½ O2(g)

is second order in NO2 with a rate constant of 0.540 M-1 s-1.
If the initial concentration of NO2 is 0.477 M, the concentration of NO2 will be
M after 12.4 seconds have passed.

Enzymes affect the reactions in living cells by changing the

Answer asap need it by wednesday morning carry out the following calculations on ph and ka of from data. i. calculate the ph of 0.02m hcl ii. calculate the ph of 0.036m naoh iii. calculate the ph of 0.36m ca(oh)2 iv. calculate the ph of 0.16m ch3cooh which has ka = 1.74 x 10-5 mol dm-3 v. calculate ka for weak acid ha which has a ph of 3.65 at 0.30m concentration vi. calculate the ka of a solution made by mixing 15.0 cm3 0.2m ha and 60.0 cm3 0.31m a-. [ph= 3.80] vii. calculate the ph of a solution made by mixing 15.0 cm3 0.1m naoh and 35.0 cm3 0.2m hcooh. [ka = 1.82 x 10-4 m]

What does a numerical subscript following an element in a chemical formula mean?