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# Stoichiometry

### Combustion Reactions - Thermochemistry

1. A boiler burns fuel which has the following composition by mass: 82% carbon, 5% hydrogen, 6% oxygen and 7% ash. (a) Find the stoichiometric A/F ratio. If the dry analysis of the products yielded the following composition by volume: 13.2% carbon dioxide, 1.5% carbon monoxide, 6.8% oxygen and 78.5% nitrogen, calculate:

### Basic Chemistry Problems

Hi, I need some assistance understanding the answers to the following multiple choice questions: 1. The weight of a body varies according to the force of gravity exerted on the body. True False 2. An anion is the a: - Positive pole in an electrical system - Subatomic part of an atom - Molecule with a +1 net charge

### Solids

Lead has an atomic radius of 175 pm and crystalizes in a face centered cubic structure. Find the mass of the unit cell in grams, the volume of the unit cell in cubic centimeters, and the density of the lead in g/cubic centimeters? I submitted this problem last night and I do not understand how you are getting the measurement

### Mass, Volume and Density of unit cell of lead

Lead has an atomic radius of 175 pm and crystallizes in a face centered cubic structure. Find the mass of the unit cell in grams, thje volume of the unit cell in cubic centimeters, and the density of lead in g/cubic centimeters?

### What is the molar mass of lead?

What is the molar mass of lead?

### What is the mass in grams of 1.00 X 10^12 lead (Pb) atoms?

What is the mass in grams of 1.00 X 10^12 lead (Pb) atoms?

### How many atoms are there in 5.10 moles of sulfur(s)?

How many atoms are there in 5.10 moles of sulfur(s)?

### Particulates breathed in per day

If a person breathes in 20m^3 of air per day and the air contains 263 micrograms of particulates per m^3, how many grams of particulates does a person breathe in per day?

### Chemical Properties of Lead and its Weighting within Water Samples

If a water sample is found to contain 0.015ppm of lead (Pb), how many grams of lead are in 3.00L of this water?

### Grams of Oxygen Produced from Potassium Chloride

The following reaction takes place: 2KClO3 -> 2KCl + 3O2 How many grams of O2 are produced when 175.0g of the KClO3 react?

### Electronic Spectra in Coordination Chemistry

The most intense absorption band in the visible spectrum of [Mn(H20)6}2+ is at 24,900 cm-1 and has a molar absorptivity of 0.038 mol -1 cm-1. What concentration of [Mn(h20)6]2+ would be necessary to give an abosorbance of 0.10 in a cell of path length 1.00.

### 6 molar solubility

The Ksubletterssp for silver(l) phosphate is 1.8x10^-18. Calculate the molar solubility of silver phosphate. show all work and all steps. thanks

### Determine how many moles are used.

In the laboratory you are instructed to add 2 drops of 0.15 M AlCl3 to 2 drops of 0.15 M NaOH. If twenty drops makes one milliliter, determine how many moles of AlCl3 are used. How many moles of NaOH are used?

### 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.

### Finding Atomic Number, Mass Number, Number of Protons

An atom of Bi contains 126 neutrons. What is the atomic number, mass number, number of protons and number of electrons?

### 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

### Calculating the Number of Molecules Present in a Sample

I need to calculate the number of molecules present in: (a) 0.650 mol propane, C3H8, a gas used in laboratories (b) a 500mg tablet of CaCO3, an antacid

### 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.

### Calculating moles in a Cl atom

Calculate the number of moles of Cl atoms in 0.873 g C2H4Cl2.