1 Chapter 7 Chemistry Empirical Formulas/molecular formulas LOOK AT: Pages 245-249.

Slides:

Advertisements

Similar presentations

Chapter 11 Empirical and Molecular Formulas

Advertisements

NOTES: 10.3 – Empirical and Molecular Formulas What Could It Be?

Percent Composition, Empirical, and Molecular Formulas

Homework Check Find the percent composition of the following: 1. A compound with g of Na and 77.4 g of O 2. Ammonium Nitrate (NH 4 NO 3 ) 3. Ca(C.

Determining Chemical Formulas Experimentally % composition, empirical and molecular formula.

Empirical Formulas. Types of Formulas The formulas for compounds can be expressed as an empirical formula and as a molecular(true) formula. Empirical.

Empirical and Molecular Formulas

Chapter 3 Percent Compositions and Empirical Formulas

1 Empirical Formulas Honors Chemistry. 2 Formulas The empirical formula for C 3 H 15 N 3 is CH 5 N. The empirical formula for C 3 H 15 N 3 is CH 5 N.

Chapter 10 II. Formula Calculations

From percentage to formula

Empirical and Molecular Formulas

Empirical and Molecular Formulas. Empirical Formula What are we talking about??? Empirical Formula represents the smallest ratio of atoms in a formula.

IIIIII C. Johannesson III. Formula Calculations (p ) Ch. 3 & 7 – The Mole.

IIIIII Suggested Reading: Pages Chapter 7 sec 3 & 4.

Percent Composition Like all percents: Part x 100 % whole Find the mass of each component, divide by the total mass.

Aim: How to determine Empirical and Molecular Formula DO NOW: Here is data from an experiment: 1.Mass of empty crucible + cover = g 2.Mass of crucible.

What Could It Be? Empirical Formulas The empirical formula is the simplest whole number ratio of the atoms of each element in a compound. Note: it is.

1 Chapter 10 “Chemical Quantities” Yes, you will need a calculator for this chapter!

Percent Composition and Molecular Formulas.  Determining the percent composition of each element in a compound  H 2 O 1. Find the molar mass of the.

Chemistry 11 Unit 11. I.Introduction: Organic chemistry is the chemistry of CARBON compounds. The name “organic” refers to how many of these compounds.

Percent Composition, Empirical and Molecular Formulas.

Unit Empirical and Molecular Formulas. Empirical Formulas Consists of the symbols for the elements combined in a compound, with subscripts showing.

Determining Chemical Formulas

IIIIII III. Formula Calculations (p ) Ch. 3 & 7 – The Mole.

Mass % and % Composition Mass % = grams of element grams of compound X 100 % 8.20 g of Mg combines with 5.40 g of O to form a compound. What is the mass.

IIIIII Formula’s The Mole. Formulas n molecular formula = (empirical formula) n n molecular formula = C 6 H 6 n empirical formula = CH Empirical formula:

Chapter 3 Empirical Formulas. Types of Formulas The formulas for compounds can be expressed as an empirical formula and as a molecular(true) formula.

Empirical Formula vs. Molecular Formula Empirical formula: the formula for a compound with the smallest whole-number mole ratio of the elements Molecular.

IIIIII Formula Calculations The Mole. A. Percentage Composition n the percentage by mass of each element in a compound.

Empirical and Molecular Formula Miss Knick HAHS. Empirical Formula O Is the simplest whole number ratio of the atoms in a compound Practice: Empirical.

Mr. Chapman Chemistry 20. Converting from grams to moles Need: Moles and Mass worksheet.

Empirical and Molecular Formulas. Chemistry Joke Q: What happens to rock that has been heated to 6.02 X degrees? A: It becomes molten!

Empirical and Molecular Formulas. Formulas  molecular formula = (empirical formula) n  molecular formula = C 6 H 6 = (CH) 6  empirical formula = CH.

USING MOLAR CONVERSIONS TO DETERMINE EMPIRICAL AND MOLECULAR FORMULAS.

Calculating Empirical Formulas

From Empirical Formulas

Calculations based on Compounds Molar mass Practice mole conversions  Check answers from methane problems  Determining formulas based on data  % composition.

C. Johannesson Ch. 11 – The Mole Molar Conversions & Calculations.

Percent Composition What is the % mass composition (in grams) of the green markers compared to the all of the markers? % green markers = grams of green.

IIIIII Molecular Formula Notes The Mole. C. Molecular Formula n “True Formula” - the actual number of atoms in a compound CH 3 C2H6C2H6 empirical formula.

IIIIII II. % Composition and Formula Calculations Ch. 3 – The Mole.

III. Formula Calculations (p )

Calculating Empirical Formulas

EMPIRICAL FORMULA VS. MOLECULAR FORMULA .

Empirical and Molecular Formulas

III. Formula Calculations (p )

The Mole Formula Calculations.

III. Formula Calculations

EMPIRICAL FORMULA The empirical formula represents the smallest ratio of atoms present in a compound. The molecular formula gives the total number of atoms.

III. Formula Calculations (p )

III. Formula Calculations (p )

Ch. 7 Determining the Formula of a Compound

Ch. 8 – The Mole Empirical formula.

Percent Composition Empirical Formula Molecular Formula

Empirical and Molecular Formulas

Empirical and Molecular Formulas

II. Percent composition

III. Formula Calculations

Empirical Formulas Unit 5.

Ch. 8 – The Mole Empirical formula.

II. Percent composition

III. Formula Calculations (p )

Empirical and Molecular Formulas

What Could It Be? Finding Empirical and Molecular Formulas.

Empirical and Molecular Formulas

Empirical and Molecular Formulas

III. Formula Calculations (p )

Empirical and Molecular Formulas

Reading Guide 10.3b Empirical Formulas Molecular Formulas

Presentation transcript:

1 Chapter 7 Chemistry Empirical Formulas/molecular formulas LOOK AT: Pages

Empirical vs Molecular Formula C2H6C2H6 CH 3 Empirical formula - Smallest whole number ratio of atoms in a compound Molecular formula true or actual ratio of the atoms in a compound.

3 Types of Formulas The formulas for compounds and molecules can be expressed as an empirical formula and as a molecular formula. Empirical Molecular CHC 2 H 2 CHC 6 H 6 CO 2 CH 2 OC 5 H 10 O 5

Calculating Empirical Formula 1. Given: mass or percent of each element. If percent, just change % to g. 2. Convert grams to moles. 3. Divide ALL mole ANSWERS by the smallest number moles. By doing this, you find the subscripts. You may have to round to a whole number….the number can only be off by a little. 4. If any of your subscripts turn out to be.25,.50, or.75, you will need to multiply by 2, 3, or 4 to get a whole number.

Practice Find the empirical formula of a compound that contains 75.0 % Carbon and 25.0% Hydrogen. Find the empirical formula for a sample of 25.9% N and 74.1% O. 5

practice A typical charcoal briquette that is used in making a BBQ fire is composed of 43.2 g of Carbon. When the Charcoal lump is burned, it combines with oxygen and the resulting compound has a mass of g. What is the empirical formula of the compound? 6

Empirical formulas of hydrates EX: A 5.00 g sample of a hydrate Copper (II) Nitrate is heated and 3.90 g of the anhydrous salt remains. Calculate the empirical formula of the hydrate. Name the hydrate. 7

Finding molecular formula from the empirical formula 1.Find the molar mass of the empirical formula 2.Divide the molar mass of the empirical formula by the molar mass of the molecular formula(will be given in the problem)--- you should get a whole number. 3.Take this number and multiply it to each subscript in the Empirical Formula. 4.The new formula is the molecular formula. 8

Molecular Formula The empirical formula for ethylene is CH 2. Find the molecular formula if the molecular mass is 28.1 g/mol?

10 Practice A compound has a molar mass of and an empirical formula of C 3 H 4 O 3. What is the molecular formula?