nomenclature
mass/moles/molecules
emp./mol. formulas
miscellaneous
100

How would you write sulfur dioxide?

SO2

100

What is the molar mass of (NH4)2HPO4?

132.06 g/mol

100

What is the difference between empirical and chemical formulas?

empirical: a formula giving the proportions of the elements present in a compound but not the actual numbers or arrangement of atoms.

molecular: a formula giving the number of atoms of each of the elements present in one molecule of a specific compound.

100

How many moles of O are there in 2.7 moles NO3?

8.1 moles O

200
How would you write ammonium phosphate?

(NH3)4PO4

200

How many moles are in 17.5 g of (NH4)2HPO4? (MM = 132.06g/mol)


0.133 moles

→ how many moles of hydrogen are there in one mole of (NH4)2HPO4?

200

What is the empirical formula of C3H12O27?

CH4O9

200

If you have 0.0153 moles of CO2, how many molecules of CO2 do you have?

9.21 x 1021 molecules CO2

→ how many atoms of O do you have?

1.84 x 1022 atoms O

300

How would you write potassium dichromate?

K2Cr2O7

→ what about rubidium chromate?


300

In comparing a balloon containing 25 grams of helium to a balloon containing 25 grams of neon, which has more atoms?

helium

300

Determine the empirical formula of polystyrene which is 92.3% C and 7.7% H. (Atomic weights: C = 12.01, H = 1.008)

CH

300

The analysis of 5.00 g of a compound showed that it contains 4.44 g of oxygen and 0.56 g of hydrogen, calculate its % H & O %

11.1% H 88.9% O

400

how do you write perchloric acid

HClO4(aq)

400

How many nitrogen atoms does one mole of nitrogen gas contain?

1.69 x 1025 Natoms

400

Determine the molecular formula of a compound with the empirical formula CH2O and a molar mass of 180 g/mol.

C6H12O6

400

Name whether the following are ionic or covalent:

Fe2O3, CCl4, NI3, CBr4, H2O

ionic, covalent, covalent, covalent, covalent
500

how is iron (III) dichromate written?

Fe2(Cr2O7)3

500

You have 25.0 g of Na, Cu, C, Pb, and Ne. Which contains the largest number of moles?

C

500

Determine the empirical formula for a compound composed of 60% C, 4.5% H, and 35.5% O

C9H8O4