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Stoichiometry

Calculation mass of alcohol in a solution (volume% is given)

A mouthwash contains 22.5% alchohol by mass. If the bottle of mouthwash contains 350 mL, what is the mass, in g, of alcohol? Using the (m/v)%= Mass of solute (g)X100 Volume of solution(mL) So far, I have: Step 1. 22.5% alcohol= 22.5g alcohol _________

Working with Osmotic Pressure

An aqueous solution of 10 g of catalase an enzyme found in the liver has a volume of 1 liter at 27 degrees Celcius. The solutions osmotic pressure at 27 degree celcius is found to be 0.745 torr. Calculate the molar mass of catalase. could you please explain how you come up with the answer to this problem? Thank-you.

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

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?

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

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(

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.

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

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

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?

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

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.

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

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

Balanced Chemical Equations - Calcium Carbonate

136. What mass of calcium carbonate is required to react with the sulfur that is produced by burning 1000 kg of coal that contains 3.6 % sulfur by mass? Using a chemical equation convert the mass of coal to a mass of sulfur dioxide, then calculate the amount of calcium carbonate needed.

Molecular mass and moles

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.

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

Hydroxide ion concentration

At 25 degrees C, 0.212 g of barium hydroxide Ba(OH)2 is dissolved completely in sufficient 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 state the assumption you must