Upon decomposition, one sample of magnesium fluoride produced 1.64 kg of magnesium and 2.58 kg of fluorine. A second sample produced 1.32 kg of magnesium.  How much fluorine (in grams) did the second sample produce?         Express your answer in grams to three significant figures.

A 12.1-g sample of Na2SO3 is mixed with a 14.6-g sample of MgSO4. What is the total mass of oxygen present in the mixture?

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.

3.83 For the reaction of nitrogen, N2, and hydrogen, H2, to form ammonia, NH3, a student is attempting to draw a particulate diagram, as shown below. Did the student draw a correct representation of the reaction? If not, what was the error the student made?

An adult human body contains 6.0 L blood, which contains about 15.5 g hemoglobin per 100.0 mL blood. The molar mass of hemoglobin is approximately 64,500 g/mol and there is 4 mol iron per 1 mol hemoglobin. A news item claims that there is sufficient iron in the hemoglobin of the body that this iron, if it were in the form of metallic iron, could make a 3-in. iron nail that weighs approximately 3.7 g. Show sufficient calculations to either support or refute the claim.

The density of a mixture of gases may be calculated by summing the products of the density of each gas and the fractional volume of space occupied by that gas. (Note the similarity to the calculation of the molar mass of an element from the isotopic masses and fractional abundances.) Assume dry air with CO2 removed is 20.96% (by volume) oxygen. 78.11% nitrogen, and 0.930% argon. Determine the density of argon.

The age of the universe is unknown, but some conclude from measuring Hubbles constant that the age is about 18 billion years old, which is about four times the age of Earth. If so, calculate the age of the universe in seconds. If you had a sample of carbon with the same number of carbon atoms as there have been seconds since the universe began, determine whether you could measure this sample on a laboratory balance that can detect masses as small as 0.1 mg.

3.107 As computer processor speeds increase, it is necessary for engineers to increase the number of circuit elements packed into a given area. Individual circuit elements are often connected using very small copper “wires” deposited directly onto the surface of the chip. In some processors, these copper interconnects are about 22 nm wide. How many copper atoms would be in a 1-mm length of such an interconnect, assuming a square cross section? (The density of copper is 8.96 g/cm3.)

Copper atoms. (a) What is the average mass of one copper atom? (b) Students in a college computer science class once sued the college because they were asked to calculate the cost of one atom and could not do it. But you are in a chemistry course, and you can do this. (See E. Felsenthal, Wall Street Journal, May 9, 1995.) If the cost of 2.0-mm diameter copper wire (99.9995% pure] is currently 41.70 for 7.0 g, what is the cost of one copper atom?

There are five hydrocarbon compounds (compounds of C and II) that have the formula C6H14. (These are isomers; they differ in the way that C and H atoms are attached. Chapter 23) All are liquids at room temperature but have slightly different densities. (a) You have a pure sample of one of these hydrocarbons, and to identify it you decide to measure its density. You determine that a 5.0-mL sample (measured in a graduated cylinder) has a mass of 3.2745 g (measured on an analytical balance). Assume that the accuracy of the values for mass and volume is plus or minus one ( 1) in the last significant figure. What is the density of the liquid? (b) Can you identify the unknown hydrocarbon based on your experiment? (c) Can you eliminate any of the five possibilities based on the data? If so, which one(s)? (d) You need a more accurate volume measurement to solve this problem, and you redetermine the volume to be 4.93 mL Based on this new informationwhat is the unknown compound?