1. Determine the amount of heat (enthalpy) produced if 25.00 grams of hexadecane is burned in excess oxygen to produce carbon dioxide and water. Ensure that your answer includes the molecular formula and a balanced chemical equation for the combustion reaction.
2. Calculate the mass of CO2 produced from 25.00 grams of hexadecane.
In: Chemistry
A.What concentration of potassium hydroxide is
needed to give an aqueous solution with a pOH of
3.720?
Molarity of potassium hydroxide =
B.What concentration of sodium hydroxide is needed to give an aqueous solution with a pH of 9.210?
Molarity of sodium hydroxide =
In: Chemistry
30.0 mL solution of 0.010 M piperidine (the active ingredient in hot pepper, the protonated form is a monoprotic weak acid with pKa= 11.123) was titrated with 0.050 M HCl. a) Find Ve (the volume of HCl at equivalent point); b) Calculate the pH at Va (the volume of HCl added) =0, ¼ Ve, Ve, and 1.1 Ve; c) Using the information from (b), sketch the titration curve for this titration. Please mark the “landmark” points on this curve.
In: Chemistry
Explain thin layer chromatography and its utility in determining the components of a mixture. Be sure to briefly explain how TLC works as well as what and how the visualization techniques work.
In: Chemistry
How does a salt effect the pH of water? Please write at least 4 sentences or more on the answer. Thank you.
In: Chemistry
1. Calculate the pH and the concentrations of all species present in a .0230 M HPO4- (Ka = 4.90 x 10-10)
2. Calculate the pH and the concentrations of all species present in a 3.20 x 10-5 M CH3CO2H (Ka = 1.70 x 10-5)
In: Chemistry
In 1783, Jacques Charles launched his first balloon filled with hydrogen gas, which he chose because it was lighter than air. This balloon, which had a volume of 31 000L at STP, reached an altitude of 1000m, where the pressure was 651 mmHg and the temperature was -9 degrees C. What was the volume, in liters, of the balloon at these conditions?
In: Chemistry
An aqueous solution containing 34.2g of an unknown molecular (nonelectrolyte) compound in 143.1g of water was found to have a freezing point of -1.5?C. Calculate the molar mass of the unknown compound.
In: Chemistry
What is the structural and functional difference between polysaccharides and glycosaminoglycans
In: Chemistry
The incredible length of biological polymers (sometimes tens of thousands of monomers) often results in the formation of a tertiary, 3-D structure. An example of this is in globular proteins. Which of these is NOT a force of attraction which usually acts between the different sections of the polypeptide chain of a globular protein?
| 1. |
Van der Waals' forces |
|
| 2. |
Hydrogen bonds |
|
| 3. |
ionic bonds |
|
| 4. |
Metallic bonds |
In: Chemistry
354 mL of 0.21 M formic acid HCOOH was mixed with 126 mL of 0.9 M NaOH. What will be the final pH?
In: Chemistry
0.10 g of Fe3O4 reacts with excess O2 to give Fe2O3 in 20.36% yield according to the following balanced equation. Calculate the theoretical yield and the actual yield of Fe2O3(s).
4Fe3O4(s) + O2(g) --> 6Fe2O3(s)
In: Chemistry
Suppose you have the following reaction at equilibrium:
C(s) + 2H2(g) = CH4(g), ΔH = −74.8 kJ
What changes are expected to occur if the pressure of the system was increased? You may select multiple answers.
|
The temperature would increase above the expected temperature increase resulting from the increased pressure. |
||
|
The concentration of H2(g) would decrease |
||
|
The amount of C(s) present would decrease |
||
|
The concentration of CH4(g) would increase |
||
|
No change in the equilibrium would occur. |
||
|
The concentration of CH4(g) would decrease |
In: Chemistry
A solution was prepared by dissolving 0.0258 mol disodium phosphate in 500.0mL of deionized water. Phosphoric acid has the following pKa values: pKa1 = 2.148 , pKa2 = 7.198 , pKa3 = 12.375.
a) What was the pH of the resulting solution?
b) What was the concentration of H2PO4- in the solution?
In: Chemistry
a) Of the chemical bonding types often found in minerals, which is the strongest and which is the weakest? Why?
b) Water molecules in ice are an example of what type of bond? Explain.
In: Chemistry