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Stoichiometry

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.

Mass equation

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 %

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.

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.

Molarity and Molality

The density of a 20.3 Molar CH3OH (methanol) solution is 0.858 gram/ml. What is the molality 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 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?

Density Problem

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.

Dilution

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

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

Density

Nickels are composed of 25% nickel and 75% copper by mass, what is its density (d of nickel = 8.902 g/cm3; d of copper = 8.95 g/cm3)?

Particles

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. 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 particles are

Concentration of Particles in Air

If a person breathes in 20m3 of air per day and the air contains 263 micrograms of particulates per m3, how many grams of particulates does a person breathe in per day?

Coal combustion

A particular coal contains 5.45% by weight of sulfur. How many grams of SO2 gas will be produced when 100.0g of the coal is combusted? S(s) + O2(g) SO2(g)

Calculating a Compound's Solubility

Question: Consider a body of water in equilibrium with solid calcium sulfate (CaSO4), for which Ksp = 4E-5 at 25 degrees Celsius. Calculate the solubility of calcium sulfate in water (in grams/liter) assuming that the other reactions are negligible.

Calculating the number of moles and from the compound's mass.

First, how many moles are present in each of the following masses? 2.58g of SrSO4 and 2.53 x10-3g of Ag2CO3. Second, going in reverse, How many grams are necessary to obtain the given number of moles? 3.20 x 10-4 moles of NaOH and 6.42 moles of AgNO3.

Radon

What does a radon level of 3pCi/L in a home mean. Should you be concerned about a radon exposure at this level? Why or Why not?

Hydroxide ion concentration using K or Kw not Ksp

At 25 degrees C, 0.212 g of barium hydroxide Ba(OH)2 (2 in lower position) is dissolved completely in sufficent water to make 0.25 litre final solution. What is the hydroxide ion concentration(in mol per litre) in this solution? Give the answer in scientific notation to an appropriate number of significant figures, and sta