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Ch.3 - Mass Relationships in Chemical Reactions
Chapter 3, Problem 48d

How many grams are in a mole of each of the following substances? (d) H2O

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Determine the molar mass of each element in the compound H_2O.
Hydrogen (H) has a molar mass of approximately 1.01 g/mol. Since there are 2 hydrogen atoms in H_2O, multiply the molar mass of hydrogen by 2.
Oxygen (O) has a molar mass of approximately 16.00 g/mol. Since there is 1 oxygen atom in H_2O, use the molar mass of oxygen as is.
Add the total mass of hydrogen and the mass of oxygen to find the molar mass of H_2O.
The result is the number of grams in one mole of H_2O.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Molar Mass

Molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol). It is calculated by summing the atomic masses of all the atoms in a molecule. For example, in water (H2O), the molar mass is derived from two hydrogen atoms and one oxygen atom, which are approximately 1 g/mol and 16 g/mol, respectively.
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Avogadro's Number

Avogadro's number, approximately 6.022 x 10^23, is the number of particles (atoms, molecules, or ions) in one mole of a substance. This constant allows chemists to convert between the number of moles and the number of individual particles, facilitating calculations in stoichiometry and chemical reactions.
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Stoichiometry

Stoichiometry is the branch of chemistry that deals with the quantitative relationships between the reactants and products in a chemical reaction. It involves using the molar mass and Avogadro's number to calculate the amounts of substances involved, enabling the determination of how many grams are present in a given number of moles.
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