Percent Composition and Chemical Formulas

The relative amounts of the elements in a compound are expressed as the percent composition.

• True

• False

The percent by ....................... of an element in a compound is the number of grams of the element divided by the mass in grams of the compound, multiplied by 100%.

• mass

• mole

• volume

• 52.9 % Aluminum, 47.1% Oxygen

• 27 % Aluminum, 71% Oxygen

• 51 % Oxygen, 49% Aluminum

Tags

NGSS.HS-PS1-7

The .........................formula of a compound gives the lowest whole-number ratio of the atoms or moles of the elements in a compound.

• empirical

• molecular

• structural

The percent composition of a compound can not be used to calculate the empirical formula of that compound.

• True

• False

The molecular formula of a compound is always the same as its experimentally determined empirical formula

• True

• False

Na3 PO4

• 42.1% Sodium, 18.9% Phosphorous, 39% Oxygen

• 42.1%Phosphorous , 18.9% Sodium, 39% Oxygen

• 42.1% Oxygen, 18.9% Phosphorous, 39% Sodium

• 70% Fe, 30% O

• 80% Fe, 20% O

• 77% Fe, 23% O

Tags

NGSS.HS-PS1-7

• A

• B

• C

• CO

• CO2

• C2O2

Tags

NGSS.HS-PS1-7