12: Lab Manual
- Page ID
- 532842
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)- 12.1: Lab 1 - Using Excel for Graphical Analysis of Data
- Using Excel for Graphical Analysis of Data
- 12.2: Lab 2 - Measurements in the Laboratory
- All measuring devices are subject to error, making it impossible to obtain exact measurements. Students will record all the digits of the measurement using the markings that we know exactly and one further digit that we estimate and call uncertain. The uncertain digit is our best estimate using the smallest unit of measurement given and estimating between two of these values. These digits are collectively referred to as significant figures.
- 12.3: Lab 3 - The Densities of Solutions and Solids
- Density is a fundamental physical property of matter. Physical properties are those characteristics of a substance that can be determined without changing the chemical identity of the substance. Other physical properties include melting point and solubility. In general, since different substances have unique densities, determining the density of an unknown substance can help identify it.
- 12.4: Lab 4 - Paper Chromatography- Separation and Identification of Five Metal Cations
- Most chemists and many other scientists must routinely separate mixtures and identify their components. The ability to qualitatively identify the substances found in a sample can be critical. For example, an environmental chemist investigating samples of polluted ground water will want to know which toxic ions might be present in a sample. Chromatography is one of the first tools used in such situations.
- 12.6: Lab 6 - Atomic Emission
- In this experiment, we will investigate the electronic structure of atoms using atomic emission
- 12.7: Lab 7 - Chemical Nomenclature Dry Lab
- Ionic compounds are composed of ions. An ion is an atom or molecule with an electrical charge. Monatomic ions are formed from single atoms that have gained or lost electrons. Polyatomic ions are formed from molecules that have gained or lost electrons. Negative ions are called anions, and are formed when an atom or molecule gains electrons. All non- metals form negatively charged ions. Positive ions are called cations, and are formed when an species loses electrons.
- 12.8: Lab 8 - Measuring Manganese Concentration Using Spectrophotometry
- Spectroscopy is one of the most powerful analytical techniques in modern science. Before the advent of spectrophotometric techniques, a chemist interested in determining the amount of a particular substance present in a sample had to analyze the sample via a series of chemical reactions specific to that species and then carefully weigh the products. Today, most routine assaying is done quickly and efficiently by means of spectroscopy.
- 12.9: Lab 9 - VSEPR Theory and Shapes of Molecules Dry Lab
- The VSEPR (Valence Shell Electron Pair Repulsion) model is used to predict the geometry of molecules based on the number of effective electron pairs around a central atom. The main postulate for the VSEPR theory is that the geometrical structure around a given atom is principally determined by minimizing the repulsion between effective electron pairs. Both the molecular geometry and the polarity of individual bonds then determine whether the molecule is polar or not.
- 12.10: Lab 10 - Titration of Vinegar
- OBJECTIVES To determine the molarity and percent by mass of acetic acid in vinegar.
- 12.11: Lab 11 - Types of Chemical Reactions
- Matter undergoes three kinds of change: physical, chemical, and nuclear. While the composition of a chemical substance is not altered by physical changes (such as freezing and evaporation), chemical changes, or reactions, result in the formation of new substances when bonds are formed and/or broken. Some relatively simple but common types of chemical reactions are illustrated in this experiment. Examples and descriptions of each reaction type appear in the following section.
- 12.12: Lab 12 - Using Periodic Properties to Identify Group 2A Cations and Group 7A Anions
- When the solubilities of compounds containing various cations combined with a given anion are compared, a solubility trend that follows the order in the periodic table is expected. For example, for the solubilities of the sulfate salts, the solubility is expected either to increase or decrease as we go down the alkaline earth family. These solubility properties will be used to identify an unknown compound containing a cation.
- 12.13: Lab 13 - Mole Ratios and Reaction Stoichiometry
- To determine these mole-to-mole ratios experimentally, a quantitative analysis of both reactions is required. Specifically, a pre-weighed mass of sodium bicarbonate/carbonate will be allowed to react with a slight excess of hydrochloric acid. The sodium chloride product will then be carefully retrieved, dried and weighed at the end of the reaction. This mass of collected sodium chloride is called an experimental yield.
- 12.14: Lab 14 - Properties of Hydrates
- It is generally possible to remove the water of hydration by heating the hydrate. Le Chatelier’s principle predicts that an addition of heat to an endothermic reaction (heat is a “reactant”) will shift the reaction to the right (product side). Heating will shift the equation of dehydration below to the right since it is an endothermic reaction. The residue obtained after heating, called the anhydrous compound, will have a different structure and texture and may have a different color than the hy
- 12.15: Lab 15 - The Properties of Oxygen Gas
- Oxygen is one of the most abundant elements on this planet. Our atmosphere is 21% free elemental oxygen. Oxygen is also extensively combined in compounds in the earths crust, such as water (89%) and in mineral oxides. Even the human body is 65% oxygen by mass. The objectives of this laboratory are: To generate (and collect) oxygen gas via the decomposition of hydrogen peroxide. To investigate the properties of oxygen, particularly as an agent of combustion.
- 12.16: Lab 16 - The Dumas Method
- In the early 19th century, Jean-Baptiste Dumas, a distinguished French chemist, created a relatively simple method for determining the molecular mass of a volatile substance. In this experiment we will use a modified version of his technique to determine the molecular mass of an unknown volatile liquid.
- 12.17: Lab 17 - The Molecular Weight of Carbon Dioxide
- OBJECTIVES To determine the molecular weight (molar mass) of carbon dioxide based on measurements of the pressure, temperature, volume and mass of a sample of the gas. To compare the experimental molecular weight to the theoretical molecular weight of carbon dioxide.
- 12.18: Lab 18 - Calorimetry and Hess's Law
- The combustion of a metal in oxygen produces the corresponding metal oxide as the only product. Such reactions are exothermic and release heat. Since it is difficult to measure the enthalpy of combustion of a metal directly, in this lab it will be determined indirectly by applying Hess’s Law of Heat Summation. Hess’s Law states that the enthalpy change of an overall process is equal to the sum of the enthalpy changes of its individual steps.