Molar mass of an element

The molar mass of an element is the mass per mole of its atoms. 

Calculate the molar mass of an element, given its isotopic composition (Example E.3). 

The tabulated molar mass of an element divided by Avogadro s number is the average mass per atom of that element, but it is not the exact mass of an individual nucleus. There are two reasons for this. First, molar masses refer to neutral atoms. The tabulated molar mass of an element includes the mass of its electrons in addition to the mass of its nucleus. Consequently, the mass of Z electrons must be subtracted from the isotopic molar mass in computing the energy of formation of a nuclide. Second, molar masses of the elements are weighted averages of... 

The molar mass of an element is the mass per mole of its atoms the molar mass of a molecular compound is the mass per mole of its molecules the molar mass of an ionic compound is the mass per mole of its formula units. The units of molar mass in each case are grams per mole (g-moD1). 

A naturally occurring sample will usually be a mixture of different isotopes. The quoted molar mass of an element is the average mass (weighted by the relative amount of each isotope present) of an atom in a naturally occurring sample of the element. 

While you can find the molar mass of an element just by looking at the periodic table, you need to do some calculations to find the molar mass of a compound. For example, 1 mol of beryllium oxide, BeO, contains 1 mol of beryllium and 1 mol of oxygen. To find the molar mass of BeO, add the mass of each element that it contains. 

O Draw a diagram that shows the relationship between the atomic mass and molar mass of an element and the Avogadro constant. 

Draw a concept map to relate the following terms molar mass of an element, molar mass... 

To convert between moles and grams, chemists use the molar mass of a substance. The molar mass of an element is the mass in grams of one mole of the element. Molar mass has the unit grams per mol (g/mol). The mass in grams of 1 mol of an element is numerically equal to the element s atomic mass from the periodic table in atomic mass units. For example, the atomic mass of copper to two decimal places is 63.55 amu. Therefore, the molar mass of copper is 63.55 g/mol. Skills Toolkit i shows how to convert between moles and mass in grams using molar mass. 

How is molar mass of an element used to convert from number of moles to mass in grams ... 

The mass of your backpack is the sum of the mass of the pack plus the masses of the books, notebooks, pencils, lunch, and miscellaneous items you put into it. You could find its mass by determining the mass of each item separately and adding them together. Similarly, the mass of a mole of a compound equals the sum of the masses of every particle that makes up the compound. You know how to use the molar mass of an element as a conversion factor in calculations. You also know that a chemical formula indicates the number of moles of each element in a compound. With this information, you can now determine the molar mass of a compound. 

If you divide the molar mass of an element by Avogadro s number, what is the meaning of the quotient (11.2)... 

The number of grams in the molar mass of an element is the same as the atomic mass. Translating atomic masses into molar masses, you can construct conversion factors that convert between the mass of an element and the number of moles of the element. 

The molar mass of an element is the mass in grams of 1 mole of that element. One molar mass of hydrogen is 1.008 g of hydrogen. One molar mass of nitrogen is 14.01 g of nitrogen. The term molar mass also applies to compounds, as will be seen later in this chapter. 

Elements. You find the molar mass of an element simply by looking up its atomic mass in the periodic table and then noting whether the element occurs naturally as individual atoms or as molecules. 

The molar mass, which expresses the equivalent relationship between 1 mole of a substance and its mass in grams, can be used as a conversion factor. We multiply by the molar mass of an element or compound (Jt, in g/mol) to convert a given amount (in moles) to mass (in grams) ... 

If you check the periodic table, you will find that copper, element 29, has an atomic mass of 63.546 amu. You know that the molar mass of an element (in g/mol) is equal to its atomic mass (given in amu). Thus, copper has a molar mass of 63.546 g/mol. By using the molar mass, you can convert 3.00 mol of copper to grams of copper. 

Alternatively, it is possible to obtain the same information from the density of the material, p. The relative molar mass of an element contains Aa atoms, where Aa is Avogadro s constant. The value of N is then given by ... 

We can extend this idea of the molar mass of an element to determine the molar mass of compounds. By analogy, the molar mass of a compound is simply the sum of the atomic weight of each element in grams multiplied by the subscript on the element in the formula of the compound. For instance, one mole of methane molecules (CH ) contains one mole of carbon atoms (molar mass = 12.0 g) and 4 moles of hydrogen atoms (4 X 1.0 g/mol =... 

The atomic mass expressed in grams is the molar mass of an element. It is different for each element. In this text, molar masses are expressed to four significant figures. 

The mass of a mole (molar mass) of an element, compound, or portion of a compound (such as the S04 ion in Na2S04) is the mass in grams equal numerically to the atomic mass, molecular mass, or formula mass. For example, given 23.0,32.1, and 16.0 for the atomic masses of Na, S, and O,... 

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