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Stoichiometry

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

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.

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

% 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

Mass Percent

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

Volume Percentage

35.0 mL of gasoline in 200.0 mL of kerosene has what volume percentage?

Molarity of a solution

What is the molarity of a solution formed from 20.0 grams of NaCl dissolved in 650.0 mL of H2O?

Nickel Chloride and Sodium Phosphate Reaction and Other Chemistry Questions

1. Nickel(11) chloride reacts with sodium phosphate to produce nickel(11) phosphate and sodium chloride. NiCl2(aq) + Na3PO4(aq) -----> Ni3(PO4)2 (s) + NaCl(aq) a. Balance the equation above b. Using the balanced equation, find out how many moles of nickel(11) chloride are required to produce 0.479 mol of nickel

Electrochemistry: mass and charge equations

Electrochemistry can be used to measure electric current in a silver coulometer. The cathode is weighed before and after the passage of the current. A silver cathode initially has a mass of 10.77 grams and its mass increases to 12.89 grams after current has flowed for 15.0 minutes. Compute the quantity of charge in coulombs a

Empirical & Molecular Formula

When phosphorus is burnt in a free supply of air, diphosphorous pentoxide is formed. During later stages of combustion in a limited supply of air, the flame becomes larger greenish and flickering. Another phosphorus oxide is formed which is a white waxy crystalline solid which melts @ 23.8 degrees C and becomes a gas @ 176 degre

Nuclear reactions: mass and time equations

A Cr3+ solution is electrolyzed using a current of 1.50 A. What mass of Cr is plated out after 24 hours, and what amperage is required to plate out 2.85 grams of Cr from a Cr3+ solution in a period of 2.50 hour?

Air bags

Air bags are activated when a severe impact causes a steel ball to compress a spring & electrically ignite a detonator cap. This causes sodium azide(NaN3) to decompose explosively: 2NaN3(s) = 2Na(s) + 3N2(g) What mass of NaN3(s) must be reacted to inflate an airbag to 70.0 L. at STP?

Limiting problem

7) Which would be used up first? How many grams of Cl2 will be produced? TiO2 + HCl = TiCl2 + Cl2 + H2O if 0.86 mole of TiO2 and 1.5 lbs of HCl react

Balancing and Limiting

Balance the following equation: UF5 + H2O = UO2F2 + UF4 + HF a) What is the maximum amount of UF4 that can be made from the 10.5 gms of UF5 and 5.0 gms of H2O b) How much of which reactant is left after the reaction stops?

Show work-Oswald process - mass and how much oxygen required?

9) Industrially, nitric acid (HNO3) is produced by the Oswald process represented by the following - what mass of NH3 is needed to produce 5 tones of HNO3? How much Oxygen is required? 4NH3 + 5O2 = 4NO = 6H20 2NO + O2 = 2NO2 2NO2 + H2O = HNO3 + HNO2