2 H2 (g) —> 2 H2O (g)

Calculate the mass of oxygen gas, O2, required to produce 12.90 moles of water, H20

Molar mass H2= 2.016 g/mol
Molar mass O2= 32.00 g/mol
Molar mass = 18.02 g/mol

Achemistry student needs to standardize a fresh solution of sodium hydroxide. he carefully weighs out of oxalic acid , a diprotic acid that can be purchased inexpensively in high purity, and dissolves it in of distilled water. the student then titrates the oxalic acid solution with his sodium hydroxide solution. when the titration reaches the equivalence point, the student finds he has used of sodium hydroxide solution. calculate the molarity of the student's sodium hydroxide solution. be sure your answer has the correct number of significant digits.

Describe at least two advantages and two disadvantages of using hydropower as a source of energy.

To prevent the presence of air, noble gases are placed over highly reactive chemicals to act as inert "blanketing" gases. a chemical engineer places a mixture of noble gases consisting of 4.37 g of he, 13.36 g of ne, and 36.65 g of kr in a piston-cylinder assembly at stp. calculate the partial pressure in torr of kr.