Magnesium has three naturally occurring isotopes with masses of 23.99 amuamu, 24.99 amuamu, and 25.98 amuamu and natural abundances of 78.99%%, 10.00%%, and 11.01%%, respectively. Calculate the atomic mass of magnesium.

Calculate the molar mass of aluminum oxide (al2o3). express your answer to four significant figures.

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.

Asample of freon gas has a volume of 2.23 liters, a pressure of 4.85 kpa, and a temperature of -1.36°c. calculate the volume at a pressure of 1.38 kpa and a temperature of 5.5°c. (show work)