Formula percentage composition

Gaseous component Chemical formula Percentage composition... [Pg.41]

If the chemical formula of a compound is already known, its mass percentage composition can be obtained from the formula. [Pg.71]

To convert the mass percentage composition obtained from a combustion analysis into an empirical formula, we must convert the mass percentages of each type of atom into the relative numbers of atoms. The simplest procedure is to imagine that we have a sample of mass 100 g exactly. That way, the mass percentage... [Pg.71]

EXAMPLE F.2 Determining the empirical formula from mass percentage composition... [Pg.72]

The mass percentage composition of a compound that assists in the coagulation of blood is 76.71 % C, 7.02% H, and 16.27% N. Determine the empirical formula of the compound. [Pg.72]

Self-TfsT F.4B The mass percentage composition of the compound thionyl difluoride is 18.59% O, 37.25% S, and 44.16% F. Calculate its empirical formula. [Pg.73]

The empirical formula of a compound is determined from the mass percentage composition and the molar masses of the elements present. [Pg.73]

F.14 Paclitaxel, which is extracted from the Pacific yew tree Taxus brevifolia, has antitumor activity for ovarian and breast cancer. It is sold under the trade name Taxol. On analysis, its mass percentage composition is 66.11% C, 6.02% H, and 1.64% N, with the balance being oxygen. What is the empirical formula of paclitaxel ... [Pg.75]

F.16 Cacodyl, which has an intolerable garlicky odor and is used in the manufacture of cacodylic acid, a cotton herbicide, has a mass percentage composition of 22.88% C, 5.76% H, and 71.36% As and a molar mass of 209.96 g-mol. What is the molecular formula of cacodyl ... [Pg.75]

J.9 You are asked to identify compound X, which was extracted from a plant seized by customs inspectors. You run a number of tests and collect the following data. Compound X is a white, crystalline solid. An aqueous solution of X turns litmus red and conducts electricity poorly, even when X is present at appreciable concentrations. When you add sodium hydroxide to the solution a reaction takes place. A solution of the products of the reaction conducts electricity well. An elemental analysis of X shows that the mass percentage composition of the compound is 26.68% C and 2.239% H, with the remainder being oxygen. A mass spectrum of X yields a molar mass of 90.0 g-moF. (a) Write the empirical formula of X. (b) Write... [Pg.101]

J.10 (a) White phosphorus, which has the formula P4, burns in air to form compound A, in which the mass percentage of phosphorus is 43.64%, with the remainder oxygen. The mass spectrum of A yields a molar mass of 283.9 g-mol. Write the molecular formula of compound A. (b) Compound A reacts with water to form compound B, which turns litmus red and has a mass percentage composition of 3.087% 11 and 31.60%... [Pg.101]

C03-0030. One of the major iron ores is an oxide with the following percentage composition Fe, 72.36% and O, 27.64%. What is the chemical formula of this ore ... [Pg.169]

Empirical formulae may also be calculated from percentage composition by mass in a similar way. [Pg.18]

A chemical formula may be used to compute the percentage composition of a compound that is, the percentage by weight of each type of atom in the compound. [Pg.147]

Determine the molecular formula of a compound of molecular weight 80 and elemental percentage composition by weight of C = 45.00, H = 7.50, and F = 47.45. Write structures for all the possible isomers having this formula. (See Exercise 1-15 for a description of how percentage composition is determined by combustion experiments.)... [Pg.28]

To determine the empirical formula of a compound, we begin by measuring the mass of each element present in a sample. The result is usually reported as the mass percentage composition, that is, the mass of each element expressed as a percentage of the total mass ... [Pg.84]

After we receive the results of a combustion analysis from the laboratory, we need to convert the mass percentage composition to an empirical formula. For this step, we need to determine the relative number of moles of each type of atom. The simplest procedure is to imagine that we have a sample of mass 100 g exactly. That way, the mass percentage composition tells us the mass in grams of each element. Then we can use the molar mass of each element to convert these masses into moles and go on to find the relative numbers of moles of each type of atom. Let s do that for vitamin C, which was once identified in this way, and suppose that the laboratory has reported that the sample you supplied is 40.9% carbon, 4.58% hydrogen, and 54.5% oxygen. [Pg.85]

Calculate the empirical formula of a compound from its mass percentage composition, Self-Test F.3. [Pg.87]

F.3 Determine the chemical formulas from the following analyses, (a) The mass percentage composition of cryolite, a compound used in the production of aluminum, is 32.79% Na, 13.02% Al, and 54.19% F. [Pg.88]

The table shows the values u0 for various percentage compositions of mixtures of CO with air, calculated according to the formula of the theory of flame propagation [5]... [Pg.282]

OAn easy way to remember the strategy for converting percentage composition to an empirical formula "Percent to mass, mass to mol, divide by small, multiply til whole". Joel S. Thompson, "A Simple Rhyme for a Simple Formula," /. Chem. Educ., Vol. 65,1988,... [Pg.98]

Derive the empirical formula of a hydrocarbon that on analysis gave the following percentage composition C = 85.63% and H = 14.37%. [Pg.29]

The approximate molar mass, calculated from the gas density data, is 89 g/mol. The empirical formula, calculated from the percentage composition data, is C2H3O with the empirical formula unit mass of 43.0. The exact molar mass must be (2)(43) = 86.0 g/mol since this is the only multiple of 43.0 (whole-number multiple) reasonably close to the approximate molecular formula of 89 g/mol. The molecule must be the equivalent of 2 empirical formulas CqHgO. [Pg.84]

Since this is an ionic compound, the empirical formula is the only formula that is possible. However, for a molecular compound, it is possible to have an empirical formula that does not represent the molecular formula. Here is a look at such an example. In the first problem, we will also show the procedure for beginning with a percentage composition, which is quite typical for these problems. [Pg.274]

Sample The percentage composition of citric acid found in lemons and other fruits is 37.5 percent C, 58.3 percent O, and 4.20 percent H by mass. What is the molecular formula of citric acid if the molecular mass is 192.14 g ... [Pg.274]

Answer The first step is to calculate the empirical formula. To begin, we need to determine the number of moles of each element. However, the percentage composition does not tell us a mass. To get around this, the commonly used technique is to assume that you have a 100.0-gram sample of the substance. Because 100.0 grams is equal to 100%, you can simply take the percentages and say that the masses are equal to that same amount in grams. From there, the problem proceeds just like the previous example ... [Pg.274]

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