...Double Displacement Reactions and Solubility 1. Write the balanced molecular equations for the reactions where the following occurred: a)Fe+3 precipitated b) Co+2 precipitated Answer: a) Fe+3 precipitated Fe(No3)3 (Aq) + 3NaI(Aq)---> FeI3(s) + 3NaNO3(aq) Fe(No3)3 (aq)+3NaBr (aq)---> FeBr3 (s) +3NaNo3(aq) Answer: b) Co+2 precipitated Co(NO3)2 (aq)+ 2NaOH ¬(aq) ---> Co(OH)2 (s)+ 2NaNO3(aq) 2. Consult your results table and write Net Ionic equations for the all of the reactions where silver precipitated out of the solution. Answer: Ag+ + Cl- ---> AgCl(s) Ag+(aq) + I+(aq) --->AgI(s) 3 Ag (aq)+ (PO4)3(aq) --->Ag3PO4(s) Ag(aq) + OH(aq)- ---> AgOH(s) 2Ag(aq) + CO3(aq) ---> Ag2CO3(s) 2Ag(aq) + SO4(aq) ---> Ag2SO4 2Ag...
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...precipitates. 3. Write balanced molecular equation, complete ionic equation, and a net ionic equation for each precipitation reaction. Materials: • Small test tubes • Various solutions Procedure: 1. Add 10-15 drops of the each reactant to a test tube. 2. Observe the results when the two solutions are combined in the test tube. 3. Record your observations for when the two solutions are mixed together and draw and label the contents of the test tube. 4. If no precipitate (ppt) is detected, write NR or no reaction. 5. Clean your test tubes when finished Reaction #1: barium chloride + sodium sulfate Observations: Balanced molecular equation: BaCl2(aq)¬ + Na2SO¬4(aq) BaSO4(s)¬ + 2NaCl(aq) Complete ionic equation: Ba2+ + 2Cl- + 2Na+ + SO42- BaSO4(s)¬ + 2Na+ + 2Cl- Net ionic equation: Ba2+ + SO42- BaSO4(s)¬ Name of product that makes the reaction occur: Barium sulfate Reaction #2: sodium carbonate + silver nitrate Observations: Balanced molecular equation: Na2CO3(aq) + 2AgNO3(aq) 2NaNO3(aq) + Ag2CO3(s) Complete ionic equation: 2Na+ + CO32- + 2Ag+ + 2NO3- 2Na+ + 2NO3- + Ag2CO3(s) Net ionic equation: CO32- + 2Ag+ Ag2CO3(s) Name of product that makes the reaction occur: silver carbonate Reaction #3: Barium chloride + lead (II) nitrate Observations: Balanced molecular equation: BaCl2(aq) + Pb(NO3)¬2(aq) Ba(NO3)¬2(aq)...
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...The solubilities of ionic substances in water vary considerably. When solutions of different ionic compounds are mixed, they sometimes react to produce a precipitate (insoluble solid). For example, if a solution of silver nitrate is added to a sodium chloride solution, a white solid, silver chloride, is produced immediately. The equation for this can be written as: AgNO3(aq) + NaCl(aq) AgCl(s) + NaNO3(aq) AgNO3(aq) + NaCl(aq) AgCl(s) + NaNO3(aq) When two solutions are mixed, precipitation will occur if one or more of the cation-anion combinations produce an insoluble compound. In the preceding example, mixing the two solutions caused insoluble silver chloride to precipitate. The other possible cation-anion combination, NaNO3, is soluble and therefore would not precipitate. If solutions of NH4NO3 and Na2CO3 are mixed, no precipitate is produced. Neither of the new cation-anion combinations, (NH4)2CO3, is an insoluble compound. It is possible to predict whether a precipitation reaction will occur when solutions of ionic compounds are mixed, by using a table of solubilities. The table indicates the solubilities of ionic substances in water under normal laboratory conditions. Solubility of common ionic substances* Soluble anions | Exceptions | Insoluble anions | Exceptions | NO3- | None | OH- | Na+, K+, Ba2+ soluble; Ca2+ slightly soluble Note: NH4OH exists as NH3(aq) | Cl- | Ag+ insoluble, Pb2+ | | | Br- | | | | I- | | | |...
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...Welcome to CH 125 Inorganic Chemistry for Microbiology Course Description This course covers inorganic reactions and phenomenon present in microbiological systems. The chemistry of the predominant biological elements of groups I to VII will be discussed. The students will explore the principles of inorganic chemical phenomenon including partially soluble substances, weak acids and bases, buffer systems and redox reactions. In addition, a basic understanding of the chemistry of the biologically important elements (H, C, N, O, K, Na, Ca, Mg, P, S, Cl and some transitional elements) will be explored. Course Learning Outcomes Upon successful completion, students will be able to: • Predict cation and anion concentrations of partially soluble solids dissolved in pure water and in a solution containing a common ion. • Apply knowledge of acids and bases in order to predict the pH of a solution containing a weak acid or base. • Demonstrate the use of common pH and redox indicators in microbiological media. • Select appropriate reagents to make a buffer having a desired pH. • Determine which compounds undergo the process of reduction and which undergo the process of oxidation. • Describe the basic chemistry of the predominant biologically important elements and their function(s) in microbiological systems. Dr. Andrew Baer Office Hours Monday: 10:30 am – 11:20 am Wednesday: 1:30 pm – 2:20 pm Thursday: 9:30 am – 10:20 am or by appointment Email:...
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...reaction of a charcoal grill is C(s) + O2(g) → CO2(g). Which of the statements below are incorrect? Why? a. 1 atom of carbon reacts with 1 molecule of oxygen to produce 1 molecule of CO2. b. 1 g of C reacts with 1 g of O2 to produce 2 g of CO2. Calculations with Chemical Formulas and Equations 21 c. 1 g of C reacts with 0.5 g of O2 to produce 1 g of CO2. d. 12 g of C reacts with 32 g of O2 to produce 44 g of CO2. e. 1 mol of C reacts with 1 mol of O2 to produce 1 mol of CO2. f. 1 mol of C reacts with 0.5 mol of O2 to produce 1 mol of CO2. Solution: a. Correct. The coefficients in balanced equations can represent amounts in atoms and molecules. b. Incorrect. The coefficients in a balanced chemical equation do not represent amounts in grams. One gram of carbon and one gram of oxygen represent different molar amounts. c. Incorrect. The coefficients in a balanced chemical equation do not represent amounts in grams. d. Correct. You might initially think that this is an incorrect representation; however, 12 g of C, 32 g of O2, and 44 g of CO2 each represent one mole of the substance, so the relationship of the chemical reaction is obeyed. e. Correct. The coefficients in balanced equations can represent amounts in moles. f. Incorrect. The amount of O2 present is not enough to react completely with one mole of carbon. Only one-half of the carbon would react, and one-half mole of CO2 would form. * Question 1 10 out of 10 points | | | The main reaction of a...
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...observations and predictions) 6. Post Lab: Part I : Single Replacement Reactions a. For every reaction that took place you must write the balanced chemical equation b. Which metal reacted the most? c. Rank your metals from more to least active Part II: Double replacement Reactions a. For every reaction where you observed precipitate, write the complete balanced molecular equation, the complete ionic equation and the net ionic equation; use the solubility rules to identify the precipitate and the states of matter of each substance participating in the reaction. b. Which cation produced the most number of precipitates? c. Write general rules of solubility that you observed. 7. Final Conclusion and error analysis To do Lab Report for Single and Double Replacement reactions : This is a formal lab report. It must be typed or written with blue or black ink. Make sure that you include the following: 1. Title 2. List of Materials 3. Safety that includes MSDS risk assessment for all the materials used ( instructions were given to you already and they are in Moodle) 4. Pre-lab questions 5. Data Table with the results obtained ( observations and predictions0 6. Post Lab: Part I : Single Replacement Reactions d. For every reaction that took place you must write the balanced chemical equation e. Which metal reacted the most? f. Rank your metals from more to least active Part...
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...www.studyguide.pk Acids, Bases and Salts THE THEORY of ACIDS and ALKALIS and a few technical terms: o Acids are substances that form hydrogen ions (H+(aq)) when dissolved in water eg hydrochloric acid HCl gives H+(aq) and Cl-(aq) ions, sulphuric acid H2SO4 gives 2H+(aq) and SO42- ions and nitric acid HNO3 gives H+(aq) and NO3-(aq) ions. o Alkalis are substances that form hydroxide ions (OH-(aq)) in water eg sodium hydroxide NaOH gives Na+(aq) and OH-(aq) ions, calcium hydroxide Ca(OH)2 gives Ca2+(aq) and 2OH-(aq) ions. Note: an alkali is a base soluble in water. o In water, there are trace quantities of H+ and OH- ions BUT they are of equal concentration and so water is neutral. o In acid solutions there are more H+ ions than OH- ions. o In alkaline solution there are more OH- ions than H+ ions. o Acids dissociate to different extents in aqueous solution. Acids that dissociate to a large extent are strong electrolytes and strong acids. In contrast, acids that dissociate only to a small extent are weak acids and weak electrolytes In a similar manner, bases can be strong or weak depending on the extent to which they dissociate and produce OH– ions in solution. Most metal hydroxides are strong electrolytes and strong bases. Ammonia, NH3, is a weak electrolyte and weak base. o BASES eg oxides and hydroxides are substances that react and neutralise acids to form salts and water. Bases which are soluble in water are called alkalis. Acids Some common acids are listed...
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...monitor the progress of the reaction. These reactions will help us gain understanding of the elements that play into a reacting aqueous solution with an ionic bond: the breaking of the intermolecular forces and use of energy define the direction and product of a chemical reaction. This experiment will reveal how temperatures can either enhance or decrease the reactions rates. Introduction Calorimetry is the measurement of the amount heat exchange in any given chemical reaction. This heat exchange can reality be measured by a thermometer placed within a closed system, as this would ensure no heat would escape. The exchange of heat or energy is a very important factor in...
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...HCO3-) react with acids to give carbon dioxide (CO2), a colorless, odorless, and slightly acidic gas. For example, the reaction of baking soda (NaHCO3) with acids such as those in lemon juice or buttermilk releases carbon dioxide which causes baked goods to rise: HCO3- + H+ CO2 (g) + H2O In this equation the sodium ion, Na+, does not participate in the reaction and is a spectator ion. It is not included in the net ionic equation, given above. Many other gases are colorless and odorless, like CO2. To confirm that the gas formed is carbon dioxide, it can be allowed to react with Ba(OH)2, barium hydroxide, to form a white insoluble precipitate of barium carbonate, BaCO3: CO2 + Ba2+ (aq) + 2 OH- (aq) BaCO3 (s) + H2O Sulfate; Cl- + H+ (aq) HCl (g). In this reaction, the sulfate ion, SO4-2, from the sulfuric acid, is a spectator ion and is not included in the net ionic equation. Another useful reaction for identification of the chloride ion is its reaction with silver nitrate to form a white precipitate of silver chloride: Cl- + Ag+ (aq) AgCl (s) As discussed above, nitrate and sodium are spectator ions and do not appear in the net ionic equation. To test the properties of the sulfate ion, you will examine the reactions of Epsom salts. This salt, MgSO4.7H2O, is used as a purgative and, as an aqueous solution, to soak tired feet. Since it dissolves in water to form Mg2+ and SO42-ions, it will not react with a solution containing SO42- and HSO4- ions...
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...value. Temperature Conversions (on the exam) Chemical Language * Elements (Na,Cl)- letters of the language * Chemical Formulas (NaCl)- words of the language Water Vs. Hydrogen Peroxide (on the exam) * The use of Hydrogen peroxide: nuclear, bomb, bleach hair,etc * Molecular formula : water: H2O, Hydrogen Peroxide : H2o2 * Empirical Formula: water HO, Hydrogen peroxide: HO * Structural Formula : water HOH, hydrogen peroxide: HOOH quetion: how many atoms of carbon, hydrogen, and oxygen are present in a single molucule of citric acid C3H5O(CO2H)3 Carbon: 6 Hydrogen :8 Oxygen: 7 Chemical Bonding * Bonds form between atoms when they share electrons * Different types of bonds: Ionic compounds: metal+nonmetal, Covalent compunds Naming Ionic Compounds Polyatomic Ions (see the syllabus) * Ions that are comprised of more than one atom; the atoms remain bound together. Naming COvalent Compounds The Mole * Def: the number of atoms contained in exactly 12g of carbon-12 * 1 mole= 6.022x10^23- avogadro's number (N) Mass-mole-number...
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...Energy The equation relating these factors is: ∆G = ∆H–T∆S, where G is free energy, H is enthalpy, S is entropy, and T is temperature (in Kelvin). Although temperature values will always be positive, entropy, enthalpy, and free energy values can be positive or negative. For a given process, a quantitative value for each factor can be calculated using the known values of the factors for each reactant involved (see Table 1) according to the general equation ∆ X°rx = Σ X°(products)–Σ X°(reactants). See if the following activity helps you better understand what these quantities really mean. Table 1 HCO3 H+ H2O (l) CO2 (g) - ∆Η° (kJ/mol) -691.1 0 -285.8 -393.5 S° (J/K mol) 94.94 0 69.9 213.6 ∆G° (kJ/mol) -587.1 0 -237.2 -394.4 Materials • • • • • vinegar baking soda thin-walled cup tablespoon measure teaspoon measure Exploration Step 1 Put about 2 tablespoons vinegar in a cup. Add a teaspoon or two of baking soda to the cup. (a) What do you observe through sight, sound, and touch? (b) What kind of change is occurring? (c) What are the formulas of the 2 major components of vinegar and of the one component of baking soda? (d) Write the overall equation and the net ionic equation for the process. Step 2 (a) Define entropy and the significance of the sign of its value. (b) Based on your observations, explain the entropy change for the system observed in Step 1. (c) Use the entropy data from Table 1 to calculate the entropy change for the net ionic equation from Step 1...
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...Tuning Surface Charge Property by Floating Gate Field Effect Transistor Song Xue1, Ning Hu2, Shizhi Qian1+ 1Institute of Micro/Nanotechnology, Old Dominion University, Norfolk, VA 23529, USA 2 Bioengineering College, Chongqing University, Chongqing 400030, P.R. China Abstract Interfacial electrokinetic phenomena, which highly depend on the surface charge property of an object in contact with an aqueous electrolyte solution, have been widely used to manipulate and transport ions, fluids and particles in micro/nanofluidic devices. Field effect transistor (FET) offers flexible and rapid control of the surface charge property, which in turn provides a more sophisticated control of the electrokinetics-based micro/nanofluidics. Tuning the surface charge property by a floating gate field effect transistor (FGFET) rather than the conventional FET is proposed and analyzed for the first time. In contrast to the conventional FET having a control gate fabricated on the outer surface of the dielectric channel wall, the FGFET has an additional floating gate electrode embedded inside the dielectric channel wall. A mathematical model has been developed to analyze the zeta potential of a planar dielectric surface regulated by the conventional FET and the FGFET techniques. Results show that the FGFET is superior to the conventional FET to tune the surface charge property of a dielectric material in contact with an aqueous solution. The FGFET has great potential to control ions, fluids...
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...persons while taking an exam. Cell phones/PDAs are to be placed in bags/backpacks which will be kept at the back of the lecture hall. Students may leave cell phones/PDAs on the front bench of the lecture hall. Students who are caught using cell phones/PDAs during an exam will be ejected from the exam and will receive a score of zero. This violation will be reported to the Dean and the Vice-Provost who will then take the appropriate disciplinary action. Only pens/pencils and scientific calculators (non-programmable and non-graphing) are allowed to be with students during exams. Students are not allowed to take an exam in a lecture section in which they are not registered. Chapter 4 – sections 4.1 – 4.8 Given a balanced chemical equation, you should be able to calculate grams (or moles) of a product (or reactant) given the grams (or moles) of another product (or reactant). Remember: grams A ( moles A ( moles B ( grams B (p. 118). Practice Example 4.1...
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...naturally occurring isotopes: 92.23% of 28Si, with an atomic weight of 27.9769 amu, 4.68% of 29Si, with an atomic weight of 28.9765 amu, and 3.09% of 30Si, with an atomic weight of 29.9738 amu. On the basis of these data, confirm that the average atomic weight of Si is 28.0854 amu. Solution The average atomic weight of silicon is computed by adding fraction-of-occurrence/atomic weight products for the three isotopes—i.e., using Equation 2.2. (Remember: fraction of occurrence is equal to the percent of occurrence divided by 100.) Thus 2.3 Zinc has five naturally occurring isotopes: 48.63% of 64Zn with an atomic weight of 63.929 amu; 27.90% of 66Zn with an atomic weight of 65.926 amu; 4.10% of 67Zn with an atomic weight of 66.927 amu; 18.75% of 68Zn with an atomic weight of 67.925 amu; and 0.62% of 70Zn with an atomic weight of 69.925 amu. Calculate the average atomic weight of Zn. Solution The average atomic weight of zinc is computed by adding fraction-of-occurrence—atomic weight products for the five isotopes—i.e., using Equation 2.2. (Remember: fraction of occurrence is equal to the percent of occurrence divided by 100.) Thus Including data provided in the problem statement we solve for as = 65.400 amu 2.4 Indium has two naturally occurring isotopes: 113In with an atomic weight of 112.904 amu, and 115In with an atomic weight of 114.904 amu. If the average atomic weight for In is 114.818 amu, calculate the fraction-of-occurrences of these two...
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