3. Calculate the mass percent of NaHCO3 based on the manufacturer's list of ingredients: 325 mg aspirin, 1000 mg citric acid, 1916 mg NaHCO,. a. Show your calculation for the mass percent of NaHCO3. b. Compare this value with your average mass percent of NaHCO, in Alka-Seltzer. How close was your experimental value to the mass percent calculated from the ingredients? Explain possible sources of error that could explain any differences.

The present average concentration (mass percent) of magnesium ions in seawater is 0.13%. A chemistry textbook estimates that if 1.00 × 108 tons Mg were taken out of the sea each year, it would take one million years for the Mg concentration to drop to 0.12%. Do sufficient calculations to either verify or refute this statement. Assume that Earth is a sphere with a diameter of 8000 mi, 67% of which is covered by oceans to a depth of 1 mi, and that no Mg is washed back into the oceans at any time.

A 0.755-g sample of hydrated copper(II) sulfate CuSo4xH2O was heated carefully until it had changed completely to anhydrous copper(II) sulfate (CuSO4 ) with a mass of 0.4183 g. Determine the value of x. [This number is called the number of waters of hydration of copper(II) sulfate. It specifies the number of water molecules per formula unit ofCuSO4 in the hydrated crystal.]

You have a pure sample of apholate, C12H24N9P3, a highly effective commercial insecticide. Calculate the molar mass of apholate. Calculate the mass of N in 100. g apholate. A sample containing 250.0 mg apholate is sprayed on an agricultural field. Calculate the mass of phosphorus in this sample of apholate; express your result in grams. Calculate the number of phosphorus atoms in this sample of apholate.