Stoichiometry

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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)?

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?

Particular Coal Combustion of Sulfur

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.

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.

Calculate the following: The molarity of 100.0 ml of solution prepared by diluting 75.0 mL of 1.5 M H2CO3.

The molarity of 100.0 ml of solution prepared by diluting 75.0 mL of 1.5 M H2CO3.

Calculate the NaOH Function Molarity

The number of mL of 0.750 M NaOH which contains 0.350 moles of NaOH.

Calculate the following: Final molarity of a solution prepared by diluting 15.0 mL of 3.0 M H2 SO4 to 150 mL.

Final molarity of a solution prepared by diluting 15.0 mL of 3.0 MH2SO4 to 150 mL.

Calculate the volume in mL of 1.50 M BaCl2 required to produce

Calculate the volume in mL of 1.50 M BaCl2 required to produce 57.2 g. of AgCl acording to the following chemical equation: AgNo^3(aq) + BaCl^2(aq) - AgCl(s) + Ba(No^3)^2(aq)

Radon Level

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

Converting grams per litre to equivalent per litre

How do I convert 2.00 x 10^-2 g/L to eq/L?

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

Working with Mole Fraction and Vapor Pressure

A solution of sodium chloride in water has a vapor pressure of 20.3 torr at 25°C. What is the mole fraction of NaCl in this solution.What would be the vapor pressure of this solution at 45°C? The vapor pressure of pure water is 23.8 torr at 25°C and 71.9 torr at 45°C

Osmotic pressure and molar mass

An aqueous solution of 10.00 g of an enzyme has a volume of 1.00 L at 29°C. The solution's osmotic pressure at 29°C is found to be 0.781 torr. Calculate the molar mass of the enzyme.

Mass percent and Molality Problem in Solutions

Assume that the density of water is 1.00 g/mL. % eth by volume = V of eth / (V of eth + V of water) * 100%. A bottle of wine contains 10.5% ethanol by volume. The density of ethanol (C2H5OH) is 0.789 g/cm3. Calculate the concentration of ethanol in wine in terms of mass percent and molality.

Osmotic Pressure and Molar Mass

Please show and explain all work, including all parts of the formulas. Osmotic Pressure. What is the osmotic pressure (in mm Hg) of a solution at 25.0°C made by dissolving 0.0135 grams of tryptophan (C11H12N2O2) in enough water to give 75.0 mL of solution? Osmotic Pressure & Molar Mass. A 0.0116-gram sample of an unkno

Mole Fraction and Conversions

What is the mole fraction of ethanol (C2H5OH) in a solution made by mixing a 20.0g sample of ethanol with 80.0g of water? What is the mole fraction of methanol (CH3OH) in a 92.5m aqueous solution? Please show all work and explain each step... It has been a while since I have taken chem and this is not my best subject.

% by weight of helium

Assume a mixture of radon and helium is separated by diffusion. What % by weight of the gases would be helium?

Mass Percent, atom percent, mass fraction, elemental fraction

To do any mass percent question one must first understand a little about fractions. If one has a fruit basket, with 3 apples, 2 oranges, 4 bananas, and a grapefruit, we could say that there is %30 apples in the basket, %20 oranges and so on if we were talking about the percentage by fruit. If we were talking about percenta

Concentration of Solutions

What is the mass percent of a solution prepared by dissolving 18.9 grams of solid into 39.5 grams of water?

Reactions and Moles

How many moles of water are made from the reaction of 2.2 moles of oxygen gas with unlimited quantities of hydrogen gas? Given the reaction:2H2 + O2 > 2H2O

Mass of Water through Vaporization

On january 1st of 2003 there were 50 kg of cucumbers in a vegetable store and they were 99% water by mass. On february 1st of 2003 they were 98% water, by mass due to loss of water through vaporization. What was the mass of cucumbers on February 1st of 2003?

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