Compound Stoichiometry

Question 1

Molar Mass / Molecular Mass

Answer 1

The average atomic mass of an element, multiplied by the number of atoms of that element in a compound, added to any other elements in the compound the same way.

Question 2

Define Mole

Answer 2

a unit that means the number of representative particles found in the molar mass of a substance.

Question 3

Representative particle for elements (except diatomics)

Answer 3

atom

Question 4

Representative particle for covalent compounds

Answer 4

molecule

Question 5

Representative particle for ionic compounds

Answer 5

formula unit

Question 6

Avagadros Number (Rounded)

Answer 6

6.02 x 10^23

Question 7

Liter to mole ratio (Volume) At STP!

Answer 7

22.4 L / 1 mol

Question 8

Percentage Composition Steps (5)

Answer 8

1 Write correct formula for the compound
2 Find the molar mass of the compound
3 Divide the total mass of the element in question present in the compound by the mass of the entire compound
4 Multiply by 100
5 Express to 2 decimal places and add a %

Question 9

Empirical Formula

Answer 9

A formula that can show the ratio of atoms in a compound.

Question 10

Empirical Formula Solving (4 steps)

Answer 10

1 divide the grams of each element given by the atomic mass of that element (if percentages are given, you can use them as grams from a 100 gram total.
2 Select the smallest value, and divide the rest of them including itself, by that value.
3 multiply all by a common factor until whole. Use as subscripts.
4 write the metal first, C, H, O, N, then in alphabetical order.

Question 11

Molecular Formula

Answer 11

Formulas that show the actual number of every different atom present, not just the ratio between.

Question 12

Molecular Formula Solving (4 Steps)

Answer 12

1 Take empirical formula
2 Find the molar mass of the empirical formula
3 Divide the given molecular mass by the molecular mass of the empirical formula
4 multiply all subscripts from the empirical formula by the resulting number