A student ran the following reaction in the laboratory at 638 K:

2HI(g) H2(g) > I2(g)

When she introduced 0.309 moles of HI(g) into a 1.00 liter container, she found the equilibrium concentration of HI(g) to be 0.248 M. Calculate the equilibrium constant, Kc, she obtained for this reaction.

Achemistry student weighs out 0.306 g of citric acid (h3c6h5o7), a triprotic acid, into a 250 ml volumetric flask and dilutes to the mark with distilled water. he plans to titrate the acid with 0.1000 m naoh solution. calculate the volume of naoh solution the student will need to add to reach the final equivalence point. be sure your answer has the correct number of significant digits.

8.98 dm3 of hydrogen gas is collected at 38.8 °c. find the volume the gas will occupy at -39.9 °c if the pressure remains constant.

Element before carbon on the periodic table