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29 terms

scientific notation

All numbers are expressed as a product of a number between 1 and 10 and a whole number power of ten.

atomic mass

The average mass of the atoms of an element.

formula mass

The sum of the atomic masses of the atoms in a formula of an ionic compound

Avogadro constant

The number of objects in a mole, 6.02 X 10 to the 23rd power.

factor label method

Problem solving method where unit labels are treated as factors.

molarity

A unit of concentration equeal to the number of moles of solute in a cubic decimeter of a solution.

atomic mass unit

One-twelve the mass of the Carbon atom - its symbol is u.

molar mass

The mass in grams of one mole of a substance.

molecular mass

The mass found by adding the atomic masses of the atoms comprising the molecule.

mole

The Avogadro constant number of objects.

formula mass

The sum of the atomic masses of all atoms in the formula unit of an ionic compound is the ___.

95.2u

The formula mass of magnesium chloride, MgCl2, is ___.

9.63 X 10 to the twenty third power

How many molecules of sulfur dioxide are present in 1.6 moles of sulfur dioxide?

mole

Which of the following units is used to represent the chemical quantity of a substance as a number of particles?

44 g

If one molecule of CO2 has a mass of 44 u, what is the mass of 6.02 X 10 to the twenty third power molecules of CO2?

0.500

The number of mole represented by 23.0 grams of nitrogen oxide, NO2, is ___.

volume of the solution in cubic decimeters

Molarity is the ratio between the moles of dissolved substance and the ___.

Atoms and molecules are extremely small

Which of the following statements explain why chemists do not count atoms and molecules directly?

6.02 X 10 to the twenty third power

The Avogadro constant is ___.

85.6 g

1.50 X 10 to the twenty third power molecules of cane sugar would have a mass of ___.

1.50 M

What is the concentration of a solution that contains 90.3 g of MgSO4 in 5.00 X 10 squared cm cubed?

kg/1000 g

Which of the following could be used as a conversion factor in solving a problem by the factor-label method?

C2H6

Which of the following could not be an empirical formula?

15.8%

What is the percentage of aluminum in aluminum silfate?

N2O5

What is the empirical formula that is 25.9% nitrogen and 74.1% oxygen?

C3Cl3N3O3

Symclosene, a disinfectant used in household cleaners, has an empirical formula of CCINO and a molecular mass of 232.432 u. What is the molecular formula of symclosene?

hydrate

A crystalline substance that contains water molecules in a definite ratio with each formula unit is a(n) ___.

1.20 X 10 to the twenty fifth power.

The formula for borax is 2(Na2B4O-) X 10H2O. The number of water molecules in two moles of borax formula units is ___.

Cu(NO3)2 X 3H2O

Which of the following is a formula for a hydrate?