Answer:
a. Amadeo Avogadro (1776-1856) was the author of Avogadro's Hypothesis in 1811, which, together with Gay-Lussac's Law of Combining Volumes, was used by Stanislao Cannizzaro to elegantly remove all doubt about the establishment of the atomic weight scale at the Karlsruhe Conference of 1860. The name "Avogadro's Number" is just an honorary name attached to the calculated value of the number of atoms, molecules, etc. in a gram mole of any chemical substance. Of course if we used some other mass unit for the mole such as "pound mole", the "number" would be different than 6.022 x 1023.
b. The first person to have calculated the number of molecules in any mass of substance was Josef Loschmidt, (1821-1895), an Austrian high school teacher, who in 1865, using the new Kinetic Molecular Theory (KMT) calculated the number of molecules in one cubic centimeter of gaseous substance under ordinary conditions of temperature of pressure, to be somewhere around 2.6 x 1019 molecules. This is usually known as "Loschmidt's Constant.
Task 2
a.
Percent composition is the percent by mass of each element present in a compound. Water, H2O, is the first example. One mole of water is 18.0152 grams. In that compound, there are two moles of H atoms and 2 x 1.008 = 2.016 grams. That's how many grams of hydrogen are present in one mole of water. this is an example. i don't know what you are describing though. i need more info for this question
b. 6.022 to 6.023 x 10^23
c. i don't know what this one is since there is nothing to describe the unknown liquid.
d. Yes a killer, but not a specific person
Explanation:
Answer:
What is spectrophotometry? It is an analytic method that it use substances light absorbance property
How can this be useful in identifying drugs? It possible compare spectra and identify problem substance
Explanation:
The way substances absorb light is unique and because of that it is possible to use spectrophotometry for substances identifying. the model spectra are measured in ideal conditions, so, it is difficult ensure the same conditions and to achieve identical spectra.
I hope I have been helpful
The expression for the Ka for the given acid is:
Ka = [H2P2O7^2-] [H3O+] /[H3P2O7^2-]
<span>Ka is the acid dissociation constant or the acidity constant. It is a measure of the acid strength when in solution. It is an equilibrium constant for the dissociation of the acid.</span>
Answer:
The correct answer is 0.6 mL.
Explanation:
We use the mathematical expression:
Ci x Vi = Cf x Vf
Where Ci is the initial concentration (5 M); Cf and Vf refers to final concentration (0.002 M) and final volume (1500 mL). With the given data, we calculate the initial volume (Vi):
Vi = (Cf x Vf)/Ci = (0.002 M x 1500 mL)/(5 M) = 0.6 mL
Therefore, we need 0.6 mL of 5 M NaCl to prepare the solution with the requested dilution.
Answer:
8.77 kilo Joules will be the total amount of heat required for both the heating and the vaporizing.
Explanation:
Moles of ethanol of ethanol = 0.200 mol
Heat required to heat 0.200 moles of ethanol = Q = 1.05 kJ
Enthalpy of vaporization of ethanol = 
Heat required to vaporize 0.200 moles of ethanol = Q'
Total heat required to fore heating and the vaporizing :
= Q + Q' = 1.05 kJ + 7.72 kJ = 8.77 kJ
8.77 kilo Joules will be the total amount of heat required for both the heating and the vaporizing.
