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    Stoichiometry

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    Mole and Weight Percent Composition

    Gas chromatographic analysis of a mixture of organic compounds gave the following peak areas (sq cm): hexane = 2.7; heptane = 1.6; hexanol = 1.8; toluene = 0.5. (a) Calculate the mole percent composition of the mixture. Assume that the response of the detector (area per mole) is the same for each component. (b) Calculate t

    Percentage AL and NH4AL(SO4)2 a Sample Before Filtering

    The aluminum in a 1.200-g sample of impure ammonium aluminum sulfate was precipitated with aqueous ammonia as Al2O3*H20. The precipitate was filtered and ignited at 1000 degrees C to give anhydrous Al2O3, which had a mass of 0.1798g. a) What is the percentage of Al in the original sample? b) What is the percentage of NH4Al(

    Determining amount of chemical consumed

    The combustion of butane in oxygen at 25 celsius to form water and carbon dioxide follows the chemical reaction: 2 C4H10(gas) + 13 O2(gas) = 8 CO2 (gas) (the = is supposed to be a forward arrow) The reaction is carried out in an excess oxygen atmosphere, and 1585 kJ heat is released. Determine the amount of butane consumed.

    Dehydrated Ethanol Reaction

    At intermediate concentrations of H2S04 in the temperature range 140-170 degrees C, ethanol may be dehydrated by two different independent reactions (see attachment). Suppose that 30% of the ethanol reacts via reaction (1) and 70% via reaction (2). How many moles of water are produced per mole of original ethanol?

    Chemical Formula for Indium

    At one time, it was thought that indium formed a chloride of formula InCl2. More recent work shows that the compound in question is actually In3[In2Cl9]. Determine the percentage by mass of indium according to each formula, and explain how the error could be made.

    Ethane Combustion Problem

    Ethane (C2H6) is burned with oxygen to form carbon dioxide and water. One hundred moles of each reactant are fed into a combustion chamber. Determine: (a) The stoichiometric ratio of O2 to C2H6. (b) The limiting reactant. (c) The percentage by which the other reactant is in excess.

    Write the Mass Equation Constant Expression

    Write the mass equation constant expression, K (subletter c) for the following reaction. Fe2O3(s) + 3H2(g) = 2Fe(s) + 3H2O(g) The equal sign is actually arrows pointing to each side of the equation.

    Balancing Equations and Limiting Reagents

    Using the initial concentration and volumes, how does one calculate the limiting reagent in each reaction below? {Please provide step by step solutions) 1# [0.1M]Pb(NO3)2 + [0.1M] Na2CrO4 --> ? initial volumes: 0.5 ml & 1 ml consecutively. 2# [0.1M]Pb(NO3)2 + [0.3M] Na3PO4 --> ? initial volumes: 1.5 ml & 0.25 ml con

    Mass % of a Compound

    The mass% of a compound is 76.71% C, 7.02%H, and x%N. Find %xN. 2) Find empirical formula of compound. Please do step by step solutions with answer please.

    Equivalent weight

    Please help me solve the problem in the attachment. First of all, I don't understand exactly what equivalent weight is. Secondly, I know that the coefficient of variation is CV = (s/x) x 100% So, what does the % analyte formula in the problem statement have to do with anything? Thanks.

    Crystalline Solid Structure

    Calculate the radius of a vanadium atom, given that V has a BCC (Body-centered cubic) crystal structure, a density of 5.96 g/cm^3, and an atomic weight of 50.9 g/mol.

    Calculating Moles and Atoms

    1) A softdrink has 70.0mg of aspartame. (nutrasweet) a) Calculate number of moles of aspartame and (b) calculate number of atoms of carbon.

    Close packing in an FCC lattice

    Potassium bromide, KBr, crystallizes like NaCl in a face centered cubic lattice. The ionic radius of K+ is 133 pm and the ionic radius of Br- is 195 pm. Assuming that all Br- ions are positioned in the face and corners of the unit cell, while the K+ ions are positioned along the edge alternating between anions, calculate the l

    Molarity and Molarity of Methanol

    The density of a 20.3 Molar CH3OH (methanol) solution is 0.858 gram/ml. What is the molarity of this solution? H20 is the solvent. Show work and thanks for your help and time.

    Ions

    Calculate the total number of ions in 14.6 g CaH2.

    Reaction - Fluorine Gas

    Elemental sulfur occurs as octatomic molecules, S8. What mass of fluorine gas is needed for complete reaction with 218.48 g sulfur to form sulfur hexaflouride?

    Limiting Unbalanced Reactants

    Suppose 358 g aluminum sulfide react with 124 g water. Al2S3 + H2O -> Al(OH)3 + H2S unbalanced! What mass of the excess reactant remains?

    Volume Reading When Density is Given

    The density of diamond is 3.51g/mL and the density of lead is 11.3g/mL. If equal masses of diamond and lead were transferred to equal volumes of water in seperate graduated cylinders, which graduated cylinder would have the highest volume reading? Explain your answer.

    Purity and Density of metals

    Determination of density has many practical applications. Is a piece of jewelry pure gold or is it an alloy perhaps of gold and silver? Give that the densities of gold and silver at 25 degrees C are 19.3 and 10.5g/mL respectively and that the volume of the alloy is the sum of the volumes of the metals used, calculate the density

    Using Stoichiometry to Solve for Moles

    Reaction: CO(g) + 2H2(g) -> CH3OH(g) Questions: 1) How many moles of each reactant are needed to produce 3.60 X 10^2g of CH3OH? 2) What are the number of grams of each reactant needed to produce 4.00 moles of CH3OH? 3) How many grams of hydrogen are necessary to react with 2.85 moles of CO?

    Density

    1) A material will float on the surface of a liquid if the material has a density of less than that of the liquid. Given density of water as 1.0g/mL, will a block having a volume of 1.2*10^4 in^3 and weighing 350 lb float or sink? 2) The density of pure silver is 10.5g/cm^3 at 20 degrees C. If 5.25 grams of pure silver pell

    Significant figures and conversions

    Please give rules for significant figures and explain as go along. 1) Put in decimal form and in scientific notation with sig. figures. a) 4.060 + 120.23 + 4.1*10^-2 b) (140) / [7.2*10^3 * 16.43 * (16.43 - 14.26)] 2) How many sig. figures? a) 100 b) 1.0*10^2 c) 1.00*10^3 d) 100. e) 0.0048 f) 0.00480 g) 4.8

    Solutions

    A solution of sodium cyanide (NaCN)is prepared by dissolving 50 grams into 500ml of solution. What is the Molarity,%(w/v), and ppm of the resulting solution.

    Successive dilutions of a solution

    A serial dilution is used to prepare solutions containing amounts(grams)of chemicals so small that they would be impossible to measure with ordinary balance. If 5.00ml of a .10 Molar salt (NaCl) solution is diluted to 500ml,then diluted to 500ml of another new solution, what is its concentration. If 5.00 ml of this solution is d

    The environmental protection agency (EPA) has proposed a new standard for microparticulates in air: a) how many of these particles are in your room? b)How many of these particles are in each 0.52-L breath you take?

    The environmental protection agency (EPA) has proposed a new standard for microparticulates in air: For particles up to 2.5 um in diameter, the maximum allowable amount is 50 ug/m3. a) If your 9.2 ft x 13.8 ft x 8.6 ft dorm room just meets the new EPA standard, how many of these particles are in your room? (Assume the particle

    Brackett Series

    1) Lines in the Brackett series of the hydrogen spectrum are cause by emission of energry accompanying the fall of an electron from outer shells to the fourth shell. The lines can be calculated using the Balmer-Rydberg equation. See Attachement for equation where m = 4, R = 1.097 x 10-2nm-1 , and n is an integer greater th