Molar Mass of Compounds Flashcards

Questions and Answers

What is one mole equivalent to?

3.25 x 10^23

6.02 x 10^23 (correct)

9.50 x 10^23

1.0 x 10^24

How do scientists determine the molar mass of a compound?

Multiply the number of moles of each element by the molar mass of that element and add the values together.

What does the periodic table tell us?

Mass of one mole of each known element.

What do the subscripts tell you in a chemical formula?

The number of moles of each element found in one mole of that compound. Signup and view all the answers

How do you calculate the mass of one mole of a compound?

Multiply the number of moles of each element by the molar mass of that element and add the values together. Signup and view all the answers

What is the molar mass of tin(IV) sulfate, Sn(SO4)2?

310.8 g/mol. Signup and view all the answers

How can you convert between mass, moles, and number of molecules?

You can use the molar mass of the substance. Signup and view all the answers

What conversion factors determine the number of moles from the number of moles of the compound?

Molar mass of compounds and Avogadro's number. Signup and view all the answers

What conversion factors determine the number of moles from the mass of a compound?

Convert the mass to moles, multiply by the ratio of atoms or ions to one mole, then multiply by Avogadro's number. Signup and view all the answers

What is the mass of 3.25 moles of sodium fluoride (NaF)?

136.461 g. Signup and view all the answers

How many molecules are in 3.25 moles of sodium fluoride (NaF)?

To determine this, you would need to use Avogadro's number. Signup and view all the answers

Study Notes

Molar Mass Basics

One mole corresponds to 6.02 x 10^23 entities (atoms, molecules, etc.) for all types of compounds.
To find the molar mass of a compound, multiply the number of moles of each element by its molar mass and sum these values.

Determining Molar Mass

Use subscripts in a chemical formula to identify the number of moles for each element.
The periodic table provides the mass of 1 mole for each known element.

Calculation Steps

Identify the molar mass from the periodic table for each element in the compound.
Count the moles of each element based on the formula.
Use the formula: Total mass = (moles of element x molar mass of element).

Example: Tin(IV) Sulfate (Sn(SO4)2)

Molar mass of tin (Sn) = 118.71 g/mol, sulfur (S) = 32.065 g/mol, oxygen (O) = 15.999 g/mol.
1 mole of Sn, 2 moles of S, and 8 moles of O in 1 mole of Sn(SO4)2.
Total molar mass calculation:
- Sn: 1 x 118.71 g/mol
- S: 2 x 32.065 g/mol
- O: 8 x 15.999 g/mol
- Molar mass of Sn(SO4)2 = 310.8 g/mol.

Conversion Between Mass, Moles, and Molecules

Use molar mass to convert between grams, moles, and the number of entities (Avogadro's number).
Conversion factors include the molar mass of the compound and Avogadro's number (6.02 x 10^23).

Example: Sodium Fluoride (NaF) Calculations

Molar mass of NaF = 22.990 g/mol (Na) + 18.998 g/mol (F) = 41.988 g/mol.
To find mass from moles: Apply conversion factor 3.25 moles x (41.988 g NaF/1 mol NaF) = 136.461 g NaF.
For molecules in 3.25 moles: Use Avogadro's number for conversion (3.25 mol NaF x 6.02 x 10^23 molecules/mol).

Description

Test your understanding of molar mass with these flashcards. Learn key concepts such as the mole definition and how to calculate the molar mass of various compounds. This resource is perfect for students studying chemistry at any level.