PERCENT COMPOSITION. 2 3 Steps for Determining Chemical Formulas 1. Determine the percent composition of all elements. 2. Convert this information into.

Slides:

Advertisements

Similar presentations

Copyright Sautter EMPIRICAL FORMULAE An empirical formula is the simplest formula for a compound. For example, H 2 O 2 can be reduced to a simpler.

Advertisements

Empirical and Molecular Formulas

Section 5: Empirical and Molecular Formulas

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

Percent Composition and Empirical Formulas

Chemistry Notes Empirical & Molecular Formulas. Empirical Formula The empirical formula gives you the lowest, whole number ratio of elements in the compound.

Empirical: based on observation and experiment

Percent Composition, Empirical and Molecular Formulas Courtesy

Molecular Formulas 1.Find empirical formula 2.Calculate molar mass of empirical formula 3.Molar mass of compound / molar mass of empirical formula (we’ll.

Percent Composition, Empirical Formulas, Molecular Formulas

Chapter 3 Percent Compositions and Empirical Formulas

Calculating Percentage Composition Suppose we wish to find the percent of carbon by mass in oxalic acid – H 2 C 2 O 4. 1.First we calculate the formula.

4.6 MOLECULAR FORMULAS. 1. Determine the percent composition of all elements. 2. Convert this information into an empirical formula 3. Find the true number.

Chemistry There are some compounds that we know have elements in fixed mass proportions. Water H 2 O  2 g : 16 g Carbon dioxide CO 2 

1.2 Formulas Define the terms empirical formula and molecular formula Determine the empirical formula and/or the molecular formula of a given.

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

Percentage Composition Chemistry 11 Ms. McGrath. Percentage Composition Chemists use molar mass to find out important information about compounds. Chemists.

Empirical and Molecular Formulas

PERCENT COMPOSITION Section 6.1 THE LAW OF DEFINITE PROPORTIONS The elements in a chemical compound are always present in the SAME proportions by mass.

Percent Composition (Section 11.4) Helps determine identity of unknown compound –Think CSI—they use a mass spectrometer Percent by mass of each element.

Percent Composition and Empirical Formulas. Terms: u The law of definite proportions describes that elements in a given compound are always present in.

Mass Percent Chemistry 11.

Chemical Formulas and Moles. Example: 1.water (C) – every molecule of water contains 2 atoms of hydrogen & one atom of oxygen - 2 molecules of H 2 O would.

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.

Percent Composition Empirical & Molecular Formulas.

3.10 Determining a Chemical Formula from Experimental Data

Unit 6: Chemical Quantities

Percentage Composition. Percent Composition Compounds are ALWAYS composed of elements in fixed ratios. This is often referred to as the Law of Definite.

Section 10.3 Percent Composition and Chemical Formulas n n OBJECTIVES: – –Describe how to calculate the percent by mass of an element in a compound.

Percent Composition, Empirical and Molecular Formulas.

Empirical & Molecular Formulas

Remember… Law of Constant Composition a compound contains elements in a certain fixed proportions (ratios), regardless of how the compound is prepared.

Percentage Composition

Percent Composition, Empirical and Molecular Formulas Courtesy

Empirical & Molecular Formulas. Percent Composition Determine the elements present in a compound and their percent by mass. A 100g sample of a new compound.

Calculating Empirical and Molecular Formulas. Calculating empirical formula A compound contains 79.80% carbon and 20.20% hydrogen. What is the empirical.

An SCH 2D1 Production C 18 H 20 BrNO 3. Today’s Agenda 2  Calculating Percent Composition  Determining Chemical Formulas.

Molecular Formulas. An empirical formula shows the lowest whole-number ratio of the elements in a compound, but may not be the actual formula for the.

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.

Unit 9: Covalent Bonding Chapters 8 & 9 Chemistry 1K Cypress Creek High School.

Percentage composition Indicates the relative amount of each element present in a compound.

Section 6.2 Molar Mass and Percent Composition 1.To understand the definition of molar mass 2.To learn to convert between moles and mass 3.To learn to.

 Shows the percent by mass of each element in a compound.

  Proportion or ratio of each element in a chemical compound  Percentage by mass of an element in a particular substance  Expressed as grams of element.

Calculating Empirical Formulas

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.

Percent Composition, Empirical and Molecular Formulas Courtesy

1.1 The Mole Concept 1.2 Formulas. Assessment Objectives Distinguish between the terms empirical formula and molecular formula Determine the.

Percent Composition - The percent composition of a component in a compound is the percent of the total mass of the compound that is due to that component.

Percent Composition - The percent composition of a component in a compound is the percent of the total mass of the compound that is due to that component.

Percent Composition, Empirical and Molecular Formulas.

Percent Composition: Is the percentage of the total mass due to each element within a compound.

Percent Mass, Empirical and Molecular Formulas. Calculating Formula (Molar) Mass Calculate the formula mass of magnesium carbonate, MgCO g +

Percent Composition. – Compounds are ALWAYS composed of elements in fixed ratios. This is often referred to as the Law of Definite Proportions. – This.

Empirical Formula.

EMPIRICAL FORMULA AND MOLECULAR FORMULA

Percentage Composition

Percent Composition, Empirical and Molecular Formulas

7.5 – NOTES Molecular Formulas

Empirical Formulas Unit 5.

Vocabulary Percent Composition -

Ch. 7-3 Percent Composition

Empirical & Molecular Formulas

Percentage Composition

Example Problems Ch

Calculating Empirical and Molecular Formulas

Chapter 11: More on the Mole

7.3 – NOTES Molecular Formulas

Empirical and Molecular Formulae

Reading Guide 10.3b Empirical Formulas Molecular Formulas

Presentation transcript:

PERCENT COMPOSITION

2 3 Steps for Determining Chemical Formulas 1. Determine the percent composition of all elements. 2. Convert this information into an empirical formula 3. Find the true number of atoms/ elements in the compound (Molecular Formula)

1. Percent Composition Compounds are ALWAYS composed of elements in fixed ratios. This is often referred to as the Law of Definite Proportions. This law states that elements are always present in the same proportions by mass in a compound. I.e. H 2 O is always 2H:1O any other proportions would not form water. H 2 O 2 is hydrogen peroxide Since compounds always form in fixed proportions, we can calculate the Percent Composition of an element in a compound. %Composition= x 100 = % Mass of element Mass of compound

1. Calculate the percentage composition of C 3 H 7 NO 2 Step 1: Find the molar mass of C 3 H 7 NO 2 M = 3(12.01) + 7(1.01) + (14.01) + 2(16.00) = g/mol %Composition= x 100 = % Mass of element Mass of compound

Step 2: Find the % of each element by dividing the mass of each element by the total mass %C = x 100 = % %H = x 100 = 7.93% %N = x 100 = 15.72% %O = x 100 = % 3(12.01) (1.01) (14.01) (16.00) Calculate the percentage composition of C 3 H 7 NO 2

2. What is the percent composition of nitrogen in N 2 O? Step 1: Find the molar mass of N 2 O M = 2(14.01) + (16.00) = g/mol %Composition= x 100 = % Mass of element Mass of compound

Step 2: Find the % of each element by dividing the mass of each element by the total mass %N= x 100 = 63.65% N 2(14.01) What is the percent composition of nitrogen in N 2 O? %Composition= x 100 = % Mass of element 44.02

3. Calculate the mass of aluminum in 28 g of Aluminum Oxide Step 1: Calculate the molar mass of aluminum oxide. Al 2 O 3 M = 2(26.98) + 3(16.00) = g/mol %Composition= x 100 = % Mass of element Mass of compound

Step 2: Calculate the % mass of aluminum in aluminum oxide. %Al = x 100 = 52.92% 2(26.98) Calculate the mass of aluminum in 28 g of Aluminum Oxide %Composition= x 100 = % Mass of element

Step 3: Find the mass of aluminum in 28g of aluminum oxide. m Al = x 28g = 15g Calculate the mass of aluminum in 28 g of Aluminum Oxide

Assignment Continue on with the following assignment

% Composition Check Point 1. What is the percent composition of carbon in carbon monoxide? 2. What is the percent composition of oxygen in carbon monoxide? 3. Calculate the mass of oxygen in 42.8g of carbon monoxide.

% Composition Check Point 1. What is the percent composition of sulfuric acid? 2. What percentage of rubidium in rubidium selenide? 3. Calculate the mass of fluorine in 24.1g of strontium fluoride.