Explore BrainMass

General Chemistry

Barium hydroxide

Write a balanced chemical equation, for the reaction that occurs, when Solid barium hydroxide, dissolves in water. Thank you

Calculating Vapor Pressure

The vapor pressure of a solution containing 53.6 g glycerin (C3H8O3) in 133.7 g ethanol (C2H5OH) is 113 torr at 40 degrees Celsius. Calculate the vapor pressure of pure ethanol at 40 degrees Celsius assuming that glycerin is a nonvolatile, nonelectrolyte solute in ethanol.

Half life

1) Radioisotopes such as aluminum -26, which is believed to have been present in the solar system when earth was formed but can no longer be detected, are known as extinct radionuclides. The half-life for the decay of aluminum -26 is 7.20 x 10 ^5 years. How many years did it take for 99.99% of the aluminum -26 to decay? If

Naming complexes

Cis-Co(en)2(NO2)2]+ trans-[Pt(NH3)3Cl3] I know that trans means opposite, cis and en I am not sure what that means but for some reason I am unable to identify the above complexes.

Element Compounds

What are element compounds and what are their properties? - Definition of element compounds - Properties of element compounds - Examples of element compounds - What element compounds are used for

De Broglie Waves

What is the de Broglie wavelength of a 145 g baseball traveling at 30.0 m/s (67.1mph)? Is the wavelength much larger or smaller than the diameter of an atom (on the order of 100 pm)?

Electromagnetic Waves: Radio Message from Mars

At its closest approach, Mars is 56 million km from Earth. How long would it take to send a radio message from a space probe of Mars to earth when the planets are at this closest distance?

Molar solubility

Calculate molar solubility of CuI in 1.0 M NaI. Assume the highest complex formed is CuI2 - .


Solid Na2SO4 is added to a solution that contains 0.150 M Ba 2+ and 0.0800 M Ca2+. Which sulfate precipitates first, BaSO4 or CaSO4? What calculations would porve this? What should be the concentration of sulfate ion for the best separation?

Wavelength from a graph

For the hydrogen spectrum, how do you find the wavelength (experimental value in nm) from a graph? I don't understand what exactly you are plotting and how to get the wavelength from the graph. For example, if your scale readings are: Violet-4.5, Blue-5.0, Yellow-6.0, Red-6.6 The same question applies to the spectra of cat

Resonance Forms of BF3

The question goes like this. Boron often forms compounds that do not comply with the octet rule that are termed electron deficient. BF3, whose structure is shown below on the left, is an example of an electron deficient compound. Note that the central boron atom is only surrounded by 6 valence electrons. The resonance struct

Chemistry Question Set

Please see the attached file for full problem description. 10a. Determine the number of CH2CH2 monomeric units, n, in one molecule of polyethylene with a molar mass of 40,000 g. 10b. What is the total number of carbon atoms in this polyethylene? 8. Equations 9.1 and 9.2 (listed below) show the polymerization of two ethy

Concentration and Dilution

Calculate the concentration of all the following. A solution of FeCl3 was prepared by dissolving 13.86 gm of FeCl3 in 2.5L of water. The following solutions were then prepared by dilution: Solution A: 75.0 mL of the above solution was diluted to 100.0mL Solution B: 100.0 mL of solution A was diluted to 2500 mL Solution C:

Determining the equation of a reaction

If 7.85 x 10 to the 24th power Sc atoms react with excess CaO, how many grams of each product will form? You will need to determine the equation of the reaction. Please show steps to solve the problem. Thank you.

Discussion of interactive/repulsive forces

A nonelectrolyte solution adsorbs on an electrically neutral solid through a liquid. Two surfaces of this type are brought close to one another in the liquid such that they interact. Will they attract or repel one another? Which equations bear this out? How does the separation distance between the two solids come into play h


Questions 9 - 11: a) COsub3^2- b) MnOsub4^- c) NHsub4^+ d) Ba^2+ e) Al^3+ Assume that you have several unknowns each consisting of an aqueous solution of a salt that contains one of the ions listed above, which ion must be present if the following observations are made of that unknown? 9) the solution is colore

Chemistry Multiple-Choice Quiz with Answer Grid.

We just finished the chapter on Dalton's Atomic Theory, atomic radius, atomic number, mass number and neutrons. I would like to review these terms with the help of a multiple chose quiz. Can you provide the answers to the following quiz, which I am only using for study purposes? Thank you. Chemistry Quiz: Mulitple-Choic

Absorption Spectroscopy

I need help describing an experiment where one could measure the value of the extinction coefficient of a solution with a concentration (c mol/L) of chlorophyll in water for a given wavelength. **This does not need to be a lengthy answer, nor does it need to describe all the materials needed---I really just need something conce

Chemistry - Gases

Chemistry - Gases Using "dimensional analysis" show that 1 L kPa = 1 J. Hints : P= F/A; 1 Pa = 1 N/m^2; energy = F x d

How long animacules in meters?

Anton Von L. a 17th century pioneer in the use of the microscope, described the microrganisms he saw as "animalcules" whose length was "25 thousandths of an inch." How long were the animalcules in meters.

Conversion Factors of Meters, Micrometers, and Kilometres

I am having a problem really understanding conversion factors between meters, centimetres, and kilometres. Where do I get the conversion factor? Can you give me a step-by-step on how to solve them? Please use conversion factors to convert 4.2 yards to meters, centimeters, micrometers and kilometers. Thank you.

Balanced Equation for Aluminum Carbonate

Write a balanced equation for: Aluminum chloride reacts with copperII carbonate Then solve: if 45 grams of copperII carbonate is used how much Aluminum carbonate will be formed(in grams).

Predict how much water is produced

For the reaction of nitric acid with calcium hydroxide, predict how much water is produced (in grams) from 46grams of calcium hydroxide.

Balance a given reaction

Balance and find moles and grams of the remaining reactants & products for the following: Barium flouride and lead nitrate react and form 6.2g of lead fluoride