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General Chemistry

Measuring Water Hardness

In an experiment for measuring water hardness in a water sample, using Atomic Absorption Spectrophotometry, I obtained a value of 173.74 ppm hardness for my water sample. Using EDTA determination, I obtained a value of 440 ppm hardness for my sample. In both these methods, I was measuring the hardness in relation specifically to

Hazardous Dyes

Question: Many dyes used in food products are classified a hazardous chemicals in their pure form. Why then can they be safely used in those food products?

General Chemistry

4.60 You have 505 ml of a 0.125M HCI solution , and you want to dilute it to exactly 0.100 M. How much water should you add?

8 precipitate of magnesium flouride

Will a precipitate of magnesium flouride form when 200.0 milliliter of 1.9x10^-3mol/Litre MgClsubnumber2 solution is added to 300.0 milliliter of 1.4x10^-2mol/Litre NaFsolution? (ksubletterssp(MgFsubnumber2)=6.9x10^-9) Briefly explain by showing your numerical calculations show work. thanks

Conversion factors

Convert the following to the required units: 550 uL (microliters) per hour to milliliters per day Please show steps

Barium hydroxide

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

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

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 - .

Precipitation

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?

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

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

Absorption Spectroscopy Experiment

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

One significant figure and one conversion problem

1) How many significant figures are there in the answer to the following problem? (8.881*.02100) + .590? 2) A parsec is 206,265 times the distance from earth to the sun. If the distance is 8.000 million miles, express the distance of a parsec in miles in scientific notation.

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

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.

Pi and Sigma bonds

Why or why isn't it possible to have pi bonds between two atoms without there being a sigma bond?

Reaction from Sodium Bisulfite Solution

In an experiment, sodium bisulfite solution is added at the end in order to destroy the unreacted bromide. What reaction is occurring here? Is HSO3- acting as an oxidizing or reducing agent? Write a balanced equation as part of your answer.

Finding volume in a molarity problem

What volume, in milliliters, of a 2.00 M aqueous KOH solution would be needed to neutralize a) 110.0 mL of 0.0550 M aqueous H2SO4? b) 45.00 mL of 2.50 M aqueous HCl?

Quantum numbers

Which element(s) has an outermost electron that could be described by the following quantum numbers: (3,1,-1,+1/2) ?