Explore BrainMass
Share

General Chemistry

Dilution Processes

I need help in solving this word problem: A corrupt barman attempts to prepare 100ml of some drink by mixing 30ml of ethanol with 70 ml of water. Does he succeed? If not, what volumes should have been mixed in order to arrive at a mixture of the same strength but of the required volume?

Precipitation calculations

Precipitation Calculations. Will a precipitate of calcium sulfate (Ksp = 2.4 x 10-5) form when 50.0 mL of 0.00150 M calcium chloride and 25.0 mL of 0.0100 M sodium sulfate are mixed? Why or why not?

Colors and Bands

What color has the smallest band in the spectrum of a tungsten light bulb? I have guessed yellow because the waves are shortest but don't know if I am right.

Total Pressure

A closed flask contains a .25 moles of O2 which exerts a pressure of .50 atm. If .75 moles of CO2 is added to the container what is the total pressure in the flask? Please provide step by step instructions with explanation.

General Chemistry - Orbitals and Configuration

Which one of the following configurations depicts an excited oxygen atom? a. 1s22s22p2 b. 1s22s22p23s2 c. 1s22s22p4 d. [He]2s22p4 e. 1s22s22p1 In a ground-state manganese atoms, the _____ subshell is partially filled. a. 4s b

Radioactive Isotope Intravenously

Your patient needs to receive 7.2mCi of a radioactive isotope intravenously. the isotope is supplied in vials containing 7.00cc of liquid and each vial has an activity of 80mCi. How many mL of the liquid should your patient receive? How to set up this problem?Step by step instructions please.

Chemical Properties

Which of the following is true of Cu-36? It has ________. a. 29 electrons b. 63 protons c. 63 neutrons d. 29 neutrons.

Which pair consist of equalities?

Which pair consist of equalities? a. 3 x 10^-3 mL and 3 L b. 7 x 10^2 g/mL and 7 x 10^-9 kg/L c. 6 x 10^2 mm and 6 x 10^-5 m d. none of these pairs are equalities Explain how you derived at the answer.

Concentration of Salt

What is the concentration of g salt per 100 g water of a saturated solution in which 3.82 g of salt are dissolved in 9.54 g of water?

Percentage Yields

In the equation CaO+3C > CaC2+CO, where 75.5 kg of CaO produces 85.9 kg of Calcium carbide, how much calcium carbide will be produced if the percentage yield is 92.4%?

Gas Laws Photosynthesizing Autotrophs

Photosynthesizing autrotrophs use water to change carbon dioxide into glucose. Oxygen is a waste product. If the Beast's rose produces 0.500 mol of glucose, what is the pressure of (O2) that forms in the 5.0 L jar covering the flower in the cold castle (11 degrees celsius)? Do not worry about how the reactants got in.

Populated Rotational State as a Function of Temperature

Using the Boltzmann distribution given below, determine Jmax (quantum number of the most intensely populated rotational state) as a function of temperature. Then find Jmax for CN+ at 298 K and 1100 K. and CN+ bond length is 0.129 nm the Boltzman distribution: (Ni/N)= (exp(-ei/KT))/(sigma j exp(-Ej/KT)).

Atmospheric Pressure Conversions

A radio station announcer reports the atmospheric pressure to be 99.6 kPa. What is the pressure in atmospheres? In millimeters of mercury?

Atomic Mass & Isotopic Abundance

The element boron consists of two isotopes, 10(superscript), 5(subscript)B and 11(superscript), 5(subscript)B. Their masses, based on the carbon scale, are 10.01 and 11.01, respectively. The abundance of 10(superscript), 5(subscript)B is 20.0%. What is the abundance of 11(superscript), 5(subscript)B?

Empirical and molecular formulae of ethylene

1. Ethylene glycol is used as automobile antifreeze. 6.38g og this compound contains 2.47g of carbon and 0.620g of hydrogen. The rest is oxygen. The molar mass is 62.0g/mole. What are the empirical and molecular formulas of ethylene glycol? (observe significant digits)

Relationships Between Common Items and Chemistry

I have proposed to show the relationship between chemistry and a basketball. My intent is to show the composition of basketballs from different time periods. My answer must be presented as a 10 minute class presentation. Help!!!

Calculate minimum OH

The solubility product of Mg(OH)2 is 1.2E-11. What minimum OH- concentration must be attained (for example, by adding NaOH) to decrease the Mg2+ concentration in a solution of Mg(NO3)2 to less than 1.9E-10 M?

Gas Constant

When do you use 0.08206 l atm versus 8.345 l atm? Can you tell me how you decipher when to use one or the other generally? Thank you.

Pressure of Oxygen Mixtures

How can i find the pressure of oxygen if it's in a mixture of .40 moles of oxygen and .20 moles of nitrogen at 1.2 atm pressure

Finding the Partial Pressure

Please discuss how to find the partial pressure of o2 when the container has .76 mol of N2, .18 mol of O2, .031 MOl of He, and .026 mol of H2 at 744mmHg.