Composition mass percent

The mass percent composition is a listing of the mass of each element present in 100 g of a compound. This percentage by mass listing is also called the compound s elemental analysis. [Pg.155]

We illustrate how the mass percent composition of a compound is related to its chemical formula using ammonium nitrate (NH4 NO3). The molar masses of NH4 NO3 and its constituent elements can be used to convert the chemical formula into mass percentages. [Pg.156]

The elemental analysis of a compound is usually determined by a laboratory that specializes in this technique. A chemist who has prepared a new compound sends a sample to the laboratory for analysis. The laboratory charges a fee that depends on the type and number of elements analyzed. The results are returned to the chemist as a listing of mass percent composition. The chemist must then figure out which chemical formula matches this composition. If a chemist has reason to expect a particular chemical formula, the observed percentages can be matched against the calculated percentages for the expected formula. This process is illustrated in Example 3-13. [Pg.156]

C03-0081. Portland cement contains CaO, Si02, AI2 O3, and FC2 O3. Calculate the mass percent composition of each compound. [Pg.190]

What is the empirical formula of stannous fluoride, the first fluoride compound added to toothpaste to protect teeth against decay Its mass percent composition is 24.25% F, 75.75% Sn. [Pg.112]

What are the empirical formulas of substances with the following mass percent compositions ... [Pg.112]

Considering your answers, which type of formula— empirical or molecular—can be obtained from elemental analysis that gives mass percent composition Explain. [Pg.81]

You take 20.0 g of a sucrose (Ci2H22On) and NaCl mixture and dissolve it in 1.0 L of water. The freezing point of this solution is found to be —0.426°C. Assuming ideal behavior, calculate the mass percent composition of the original mixture, and the mole fraction of sucrose in the original mixture. [Pg.863]

How do we define the mass percent composition of a solution Give an example of a solution, and explain the relative amounts of solute and solvent present in the solution in terms of the mass percent composition. [Pg.503]

Mass Percent Composition from a Chemical Formula 181... [Pg.165]

Another way to express how much of an element is in a given compound is to use the element s mass percent composition for that compound. The mass percent composition or simply mass percent of an element is the element s percentage of the total mass of the compound. For example, the mass percent composition of sodium in sodium chloride is 39%. This information tells us that a 100-g sample of sodium chloride contains 39 g of sodium. The mass percent composition for a compound can be determined from experimental data using the formula ... [Pg.180]

We can use mass percent composition as a conversion factor between grams of a constituent element and grams of the compoxmd. For example, we just saw that the mass percent composition of sodium in sodium chloride is 39%. This can be written as ... [Pg.180]

EXAMPLE 6.8 Using Mass Percent Composition as a Conversion Factor The FDA recommends that adults consume less than 2.4 g of sodium per day. Flow many grams of sodium chloride can you consume and still be within the FDA guidelines Sodium chloride is 39% sodium by mass. ... [Pg.180]

SKILLBUILDER 6.8 Using Mass Percent Composition as a Conversion Factor... [Pg.181]

In the previous section, we learned how to calculate mass percent composition from experimental data and how to use mass percent composition as a conversion factor. We can also calculate the mass percent of any element in a compound from the chemical formula for the compound. Based on the chemical formula, the mass... [Pg.181]

Suppose, for example, that we want to calculate the mass percent composition of Cl in the chlorofluorocarbon CCI2F2. The mass percent of Cl is given by ... [Pg.181]

The units (%) are correct. The answer makes physical sense. Mass percent composition should never exce 100%. If your answer is greater an 100%, you have made an error. [Pg.182]

Acetic acid (HC2H3O2) is the active ingredient in vinegar. Calculate the mass percent composition of O in acetic acid. FOR MORE PRACTICE Example 6.20 Problems 79,80,81,82,83,84. [Pg.182]

CAN YOU ANSWER THIS Fluoride is often added to water as sodium fluoride (NaF). What is the mass percent composition of F in NaF How many grams of NaF should be added to 1500 L of water to fluoridate it at a level of 1.0 mg F /L ... [Pg.183]

In Section 6.7, we learned how to calculate mass percent composition from a chemical formula. But can we go the other way Can we calculate a chemical formula from mass percent composition This is important because laboratory analyses of compounds do not often give chemical formulas directly rather, they give the relative masses of each element present in a compound. For example, if we decompose water into hydrogen and oxygen in the laboratory, we could measure the masses of hydrogen and oxygen produced. Can we determine a chemical formula for water from this kind of data ... [Pg.183]

We just learned how to go from the chemical formula of a compound to its mass percent composition. Can we also go the other way ... [Pg.183]

A laboratory analysis of aspirin determines the following mass percent composition ... [Pg.185]

Ibuprofen, an aspirin substitute, has the mass percent composition C 75.69% H 8.80% O 15.51%. Calculate the empirical formula of the ibuprofen. [Pg.185]

A compound with the following mass percent composition has a molar mass of 60.10 g/mol. Find its molecular formula. C 39.97% H 13.41% N 46.62%... [Pg.187]

Write down (or calculate) the masses of each element present in a sample of the compound. If you are given mass percent composition, assume a 100-g sample and calculate the masses of each element from the given percentages. [Pg.193]

A laboratory analysis of vanillin, the flavoring agent in vanilla, determined the mass percent composition C, 63.15% H, 5.30% O, 31.55%. Determine the empirical formula of vanillin. [Pg.193]

What is the mathematical formula for calculating mass percent composition from a chemical formula How are the empirical formula and the molecular formula of a compound related ... [Pg.195]

A 2.45-g sample of strontium completely reacts with oxygen to form 2.89 g of strontium oxide. Use this data to calculate the mass percent composition of strontium in strontium oxide. 72. A 4.78-g sample of aluminum completely reacts with oxygen to form 6.67 g of aluminum oxide. Use this data to calculate the mass percent composition of aluminum in aluminum oxide. [Pg.199]

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