General Chemistry (Q#3)

45問 • 1年前

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(also molecular mass or molecular weight) is the sum of the masses of the atoms that make up the formula unit or molecule of a substance.

molar mass

is the amount of a substance that has the same number of particles (molecules, formula units, or atoms) as there are atoms in 12 grams of C-12. The number of particles in 1 mole of any substance is given by Avogadro's number, named after the Italian scientist Amedeo Avogadro (1776-1856). The value of Avogadro's number

mole

For any (?) the value of Avogadro's number means that 1 mole of this substance contains 6.022 * 10 ^ 23 molccules. This number also means that 1 mole of any ionic compound contains 6.022 * 10 ^ 23 formula units. Moreover, 1 mole of any monatomic element contains 6.022 * 10 ^ 23 atoms

molecular compound or diatomic element

1 mole of any monatomic element contains (?)

6.022*^23 atoms

compound gives the percent by mass of each element in the compound. The percent or percentage by mass of each element in a compound can be obtained by dividing the mass of the element in one mole of the compound by the mass of one mole of the compound and multiplying the quotient by 100%. The formula for the percent by mass is given below.

percentage composition

compound shows the ratio of the numbers of atoms of the elements of the compound in terms of the smallest possible positive integers

empirical formula

On the other hand, the molecular formula of a compound gives the actual number of atoms of each element in one particle of the compound. The empirical formula can be determined from the percentage composition of the compound.

molecular formula

0.50 0.10 0.25 0.30 0.75 0.70 0.20 0.90 0.40 0.33 0.60 0.67 0.80

24455551010101033

The ratio of the numbers of (?) represents the ratio of the numbers of (?) of the elements in the compound. To find the integers that represent the numbers of atoms in the empirical formula, we divide each number of moles by the least number of moles.

mole atom

The only decimal part in the number of atoms is 0.50. To convert this decimal part to a positive integer, we use the multiplier

the relationship of the masses of the reactants and products in a chemical reaction. For a given mass of a substance in a reaction, the mass of any other substance in the reaction can be obtained by using the coefficients of the balanced chemical equation and the molar masses of the substances involved. The amounts obtainable from a balanced equation are called stoichiometric amounts. The Law of Conservation of Mass, that is the sum of the masses of the reactants is equal to the sum of the masses of the products, can be used in checking the values of the masses obtained.

stoichiometry

The amounts obtainable from a balanced equation

stoichiometric amounts

(?) that is the sum of the masses of the reactants is equal to the sum of the masses of the products, can be used in checking the values of the masses obtained.

the law of conservation of mass

the amounts of two reactants are not the stoichiometric amounts, one of the reactants will be used up if the amounts of two

limiting reactant

Some of the other reactant remains unreacted when the reaction has completed. This reactant is called (?) (or excess reagent).

excess reactant

The (?) is the one that is used in stoichiometric calculations.

limiting reactant

In a chemical reaction, the (?) is the stoichiometric amount of a certain product on a chemical reaction

theoretical yield

the amount of this is provered after based on the amount of the limiting reactant hield because some of the past theoretical yield unrecovered from the reaction vessel

actual yield

The (?)is after the reactions and is given by the formula

percent yield

The Sl unit for amount of a substance. The amount that contains a number of objects equal to the number of atoms in exactly 12g of Carbon-12.

mole

also gram-molecular weight) the mass of a mol of entities (atoms, molecules, or formula units) of a substance, in units of g/mol.

molar mass

also molecular weight) The sum of atomic masses of a formula unit of a compound, in unit of amu

molecular mass

A formula that shows the actual number of atoms of each element in a molecule.

molecular formula

A chemical formula that shows the lowest relative number of atoms of each element in a compound.

empirical formula

A statement that uses chemical formulas to express the identities and quantities of substances involved in a chemical or physical change.

chemical equation

have defined the unified atomic mass unit as the unit of mass for atoms: The amu is defined as:

chemist

indicates the number ratios of combining atoms.

chemical formula of a compound

(or molecular weight) is the sum of the atomic masses (in amu) in a single molecule.

molecular formula

is the sum of atomic masses (in amu) in a single ionic formula unit.

formula mass

The (?) bridge the mass of 1 atom in amu to the mass of 1 mole of atoms in grams.

mole

links Avogadro's Number of atoms or molecules to their mass in grams.

mole

the common name of a mineral sodium tetraborate, an industrial cleaning adjunct, Na2B4O7

borax

The formula of a compound as it actually exists according to experimental data. It is a multiple of the empirical formula.

molecular formula

The simplest formula for a compound that gives rise to the smallest set of whole numbers of atoms.

empirical formula

Compounds that have the same % mass of its elements have the same (?)

empirical formula

A laboratory technique called (?) can determine the % by mass of each element in a compound

elemental analysis

are symbolic representations of "what happens" in a chemical reaction

chemical equation

A mass law stating that the total mass of substances does not change during a chemical reaction.

the law of conservation of mass

There are five basic types of chemical reactions, namely

decomposition combination single displacements double displacement combustion

involves the splitting of a substance (a compound) into more substances

decomposition

two or more substances come together only one substance

combination

An element displaces another element in a and. A double displacement reaction (or metathesis

single displacement

is the reaction of a substance with oxygen. In this chapter we 1 mainly with the combustion of hydrocarbons (organic compounds made up of carbon and n atom) and organic compounds that are composed of carbon, hydrogen, and oxygen atoms

combustion

Is the relationship of the masses of the reactants and products in a chemical reaction. For a given mass of a substance in a reaction, the mass of any other substance in the reaction can be obtained by using the coefficients of the balanced chemical equation and the molar masses of the substances involved

stoichiometry

The amounts obtainable from a balanced equation are called

stoichiometry amounts

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Paula Tapnio · 55問 · 2年前

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