Unit 4 Chemical Quantities Quiz Review

Compared with a mole of gold atoms, a mole of aluminum atoms

• has more atoms.

• has fewer atoms.

• has the same number of atoms.

• cannot be determined because gold is magnetic.

Tags

NGSS.HS-PS1-7

The molar mass of an element is numerically equal to

• the element’s average atomic mass.

• the element’s average atomic number.

• the number of electrons possessed by an element.

• the percentage composition of the element by mass.

To calculate the number of atoms present in a mole of an element, you would (a)   Avogadro’s number By the number of moles.

The chemical formula for an IONIC compound represents one ________.

• formula unit.

• ion.

• molecule.

• cation.

You would need to multiply ________ by the number of each element inside the parentheses to calculate the molar mass for Mg(NO3)₂

• one

• two

• three

• zero

The simplest whole-number ratio of moles of each element in a compound is known as the ________.

• percent composition.

• empirical formula.

• Stock formula.

• molecular formula.

The empirical formula may not represent the (a)   composition of an ionic compound, molecular compound, or crystal.

What can percent composition tell you about a compound?

• How much you need of each element for combining

• The composition (makeup) of a substance based on mass

• The amount needed to cause a precipitate to form

• nothing

The molar mass of a molecule (Ex. SO₂) is found by

• adding the masses of all the atoms in the molecule.

• dividing the total mass of all the atoms in the molecule by 6.022 x 10²³

• multiplying the total mass of all the atoms in the molecule by 6.022 x 10²³

• dividing the total mass of all the atoms in the molecule by the total number of atoms.

The TOTAL amount of atoms present in one formula unit of calcium acetate, Ca(C₂H₃O₂) is ___

• 4

• 8

• 15

• 16

Tags

NGSS.MS-PS1-1