Chemical Formulas: Formula Mass & Molar Mass. Subscripts in Chemical Formulas subscripts show # atoms of each element subscripts show # atoms of each.

Slides:

Advertisements

Similar presentations

Molar Mass of Compounds

Advertisements

SKILLS Project Calculating Molar Masses. What are molar masses? A molar mass is the weight, in grams, of a mole of any element or compound. Each element.

7.3 USING CHEMICAL FORMULAS APRIL 27, USING CHEMICAL FORMULAS Formula Masses: Sum of all the average atomic masses of all atoms represented.

1 By definition: 1 atom 12 C “weighs” 12 amu On this scale 1 H = amu 16 O = amu Atomic mass is the mass of an atom in atomic mass units (amu)

60,200,000,000,000,000,000, x

Chapter 8 Chemical Composition Chemistry B2A. Atomic mass unit (amu) = × g Atomic Weight Atoms are so tiny. We use a new unit of mass:

 Molar mass is the mass in grams of one mole of particles (atoms, ions, molecules, formula units).  Equal to the numerical value of the average atomic.

Determining Chemical Formulas

Honors Chemistry Section 7.3. A chemical formula indicates: ◦the elements present in a compound ◦the relative number of atoms or ions of each element.

Topic: Formula Mass Write the chemical formula based on the structural formula below C2H6O2C2H6O2.

1) )3.4 x ) )5.6 x 10 3 Remembering Scientific Notation…..

7.3 Using Chemical Formulas  Review  Mole: SI unit for the amount of a substance (contains avogadro’s number of particles)  Avogadro’s Number:

Chapter 2 Atoms, Molecules and Ions. Formula Weight & Molecular Weight The FORMULA WEIGHT of a compound equals the SUM of the atomic masses of the atoms.

 Empirical and Molecular Formulas and Percent Composition Unit 7: Stoichiometry – Part III Mrs. Callender.

The Mole and Chemical Composition

(4.3) The Mole and Molar Mass. THE MOLE IS THE SI UNIT FOR AMOUNT OF A SUBSTANCE. the mole represents 6.02 x particles. used for small particles.

Formula Stoichiometry. What is stoichiometry? Deals with the specifics of QUANTITY in chemical formula or chemical reaction. Deals with the specifics.

Chemical Measurements Unit 1: Stoichiometry Chapter 10 – The Mole.

The Mole Theory Molar Mass. Mass of a Mole o Molar Mass- the mass of a mole of any element or compound (in grams) o Also called: o Formula mass – sum.

Chapter 7: Chemical Formulas and Chemical Compounds

Unit 6: Chemical Quantities

Molar Mass and Molar Conversions Chapter 3 part III.

Chapter 7 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

 Dalton used the percentages of elements in compounds and the chemical formulas to deduce the relative masses of atoms  Unit is the amu(atomic mass.

Using Molar Mass as a Conversion Factor.  A molar mass is the mass in grams of one mole of a substance.  One mole of any substance contains Avogadro’s.

Atoms and Molecules Formula Unit Mass The formula unit mass of a substance is a sum of the atomic masses of all atoms in a formula unit of a compound.

Empirical Formula Calculations Problem: A compound is found to contain the following % by mass: 69.58% Ba 6.090% C 24.32% O What is the empirical formula?

Quantities in Chemistry The Mole and Molar Mass. Mole Review A Mole is a unit of measurement in chemistry. It represents 6.02 x of an entity. One.

Molar Mass of ionic compounds. Molar Mass Molar mass- same as atomic mass but for a compound rather than an atom. To determine the molar mass of any compound.

The Mole Mole Calculations. Molar Mass mass of one mole of a substance units: grams/mole equal to the ATOMIC MASS of the element, rounded to two numbers.

Understanding the mole is critical for your future success in chemistry as it is used in most chemical calculations. The Mole Chemistry 8(A)

The Mole and Molar Mass.

J OURNAL #67 What is a chemical formula? Provide an example of a chemical formula.

 How do we use these?  These indicate which of the elements make up a substance.  These also indicate the number of ions or atoms that make up a given.

Percentage Composition. Percent partwhole X 100% mass of element mass of compound X 100% X 100% percent by mass =

The Mole Calculating -Molecular Weight -Formula Weight -Molar Mass.

MOLAR MASS Molar mass of a substance = mass in grams of one mole of the substance. A compound’s molar mass is NUMERICALLY equal to its formula mass. Formula.

Chemical Reactions Balancing Equations. n In order to show that mass is conserved during a reaction, a chemical equation must be balanced n You do this.

Formula massMolar mass Units: amuUnits: grams/mole Sum of avg atomic masses of all atoms represented in the formula Numerically equal to the formula mass.

THE MOLE Measuring Matter. What is a mole? In Chemistry, a mole is the unit used to measure the amount of a substance represented by the coefficient in.

Christopher G. Hamaker, Illinois State University, Normal IL © 2005, Prentice Hall The Mole Concept.

Mass Relationships in Chemical Reactions Chapter 3.

MOLAR MASS CHAPTER 7-2.

Determining Chemical Formulas

Chapter 7-4: Determining Chemical Formulas

Formula Mass of Compounds

The Mole: A Measurement of Matter

Chemical Formulas: Formula Mass & Molar Mass

Remembering Scientific Notation…..

Empirical Formulas.

Chapter 7 – Chemical Formulas and Chemical Compounds

Chemical Formulas: Formula Mass & Molar Mass

Unit 7: The Mole (Chapter 10)

Simplest Chemical formula for a compound

The Mole Unit 3.

Chemical Quantities.

Chemical Formulas & Formula Mass

Molar Mass of ionic compounds

Calculation Of Molar Mass

Chemical Composition Mole (mol) – The number equal to the number of carbon atoms in grams of carbon. Avogadro’s number – The number of atoms in exactly.

Percentage Composition

Ch. 7: Chemical Formulas and Compounds

Unit 8 Stoichiometry.

Ch. 7: Chemical Formulas and Compounds

Add to U7-3 Warm-Ups Ca3(PO4)2 1 mol 3 mol Ca 2 mol P 8 mol O

MOLAR MASS OF A SUBSTANCE

Notes Ch. 10.3a Calculating Percent Composition

Presentation transcript:

Chemical Formulas: Formula Mass & Molar Mass

Subscripts in Chemical Formulas subscripts show # atoms of each element subscripts show # atoms of each element in representative unit in representative unit subscripts after parentheses refer to everything inside ( ) subscripts after parentheses refer to everything inside ( )

Molar mass of an element molar mass is mass (in grams) of 1 mole of any pure substance molar mass is mass (in grams) of 1 mole of any pure substance molar mass of element is: molar mass of element is: numerically equal to atomic mass, but … numerically equal to atomic mass, but … units change from amu to grams per mole (g/mol) units change from amu to grams per mole (g/mol)

Molar mass of elements Na has atomic mass of amu Na has atomic mass of amu molar mass = grams/mol molar mass = grams/mol K has atomic mass of amu K has atomic mass of amu molar mass = grams/mol molar mass = grams/mol Ca has atomic mass of amu so Ca has atomic mass of amu so molar mass = grams/mol molar mass = grams/mol

Round masses to whole number Na = grams rounds to 23g K = grams rounds to 39g Ca = grams rounds to 40g rounds to 40g

Molar Mass MOLAR mass: always refers to mass in grams per mole (g/mol) MOLAR mass: always refers to mass in grams per mole (g/mol) formula mass (FM) or gram formula mass (GFM): refers to mass in grams (g) formula mass (FM) or gram formula mass (GFM): refers to mass in grams (g) for amounts other than one mole for amounts other than one mole

Mole to Mass conversions use PT for conversions involving mass use PT for conversions involving mass unless you want to memorize the masses of all the elements!!

Molar Mass of Compounds = to sum of masses of all atoms in compound's formula = to sum of masses of all atoms in compound's formula round atomic masses to whole number round atomic masses to whole number ex: H 2 O 2 H’s = 2 x 1g = 2g 2 H’s = 2 x 1g = 2g 1 O = 1 x 16g = 16g 1 O = 1 x 16g = 16g FM of H 2 O is sum: 2g + 16g = 18g FM of H 2 O is sum: 2g + 16g = 18g molar mass of H 2 O is 18g/mol molar mass of H 2 O is 18g/mol

Molar Mass of Compounds CH 4 1 C = 1 x 12g = 12g 1 C = 1 x 12g = 12g 4 H’s = 4 x 1g = 4g 4 H’s = 4 x 1g = 4g FM is sum = 4g + 12g = 16g FM is sum = 4g + 12g = 16g molar mass is 16g/mol molar mass is 16g/mol

challenge: find FM of CuSO 45H 2 O 4Ba 3 (PO 4 ) 2