Determine the mass (in g) of Na2CO3 that contains 3.43 × 1023 O atoms.

Arrange the following substances in order of increasing mass percent of nitrogen. a. NO b. N2O c. NH3 d. SNH

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.

Chalky, white crystals in mineral collections are often labeled borax, which has the molecular formula Na2B4O7 10H2O, when actually they are partially dehydrated samples with the molecular formula Na2B4O7 5H2O, which is more stable under the storage conditions. Real crystals of borax are colorless and transparent. (a) Calculate the percent mass that the mineral has lost when it partially dehydrates. (b) Is the percent boron by mass the same in both compounds?

Express the composition of each of the following compounds as the mass percents of its elements. a. formaldehyde, CH2O b. glucose, C6H12O6 c. acetic acid, HC2H3O2

Combustion analysis of 1.00 g of the male sex hormone, testosterone, yields 2.90 g of CO2 and 0.875 g H2O. What are the mass percents of carbon, hydrogen, and oxygen in testosterone?

Complete the following table for TNT (trinitrotoluene), C7H5(NO2)3.

3.96 Methyl cyanoacrylate is the chemical name for the substance sold as Super Glue, and it has the chemical formula C5H5NO2. Calculate the number of molecules of this substance in a 1.0-ounce tube of Super Glue, assuming that the glue is 80% methyl cyanoacrylate by mass.

Morphine, a narcotic substance obtained from opium, has the molecular formula C17H19NO3. What is the mass percentage of each element in morphine (to three significant figures)?

3.116 The simplest approximate chemical formula for the human body could be written as C728H4850O1970N104Ca24P16K4S4Na3Cl2Mg. Based on this formula, describe how you would rank by mass the ten most abundant elements in the human body.