Why is substitution of a Pro amino acid in the middle of an alpha-helix always disruptive?
In: Chemistry
Consider the titration of 50.0 mL of 0.20 M NH3 (Kb=1.8×10−5) with 0.20 M HNO3. Calculate the pH after addition of 50.0 mL of the titrant.
In: Chemistry
In: Chemistry
Use tabulated half-cell potentials to calculate ?G?rxn for each of the following reactions at 25 ?C
Pb2+(aq)+Mg(s)?Pb(s)+Mg2+(aq) answer in kJ
Br2(l)+2Cl?(aq)?2Br?(aq)+Cl2(g)
Br2(l)+2Cl?(aq)?2Br?(aq)+Cl2(g)
In: Chemistry
In: Chemistry
Ethanol is produced commercially by the hydration of ethylene:
C2H4+H2O-->C2H5OH
Some of the product is converted to diethyl ether in side reaction
2C2H5OH-->(C2H5)2O+H2O
The feed to the reactor contains ethylene,steam,and an inert gas. A sample of the reactor effluent gas is analyzed and found to contain 43.3 mole% ethylene, 2.5% ethanol, 0.14% ether, 9.3% inerts, and the balance water.
a. Take as a basis 100 mol of effluent gas, draw and label a flowchart, and do a degree-of-freedom analysis based on atomic species to prove that the system has zero degrees of freedom?
b. Calculate the molar composition of the reactor feed, the percentage conversion of ethylene, the fractional yield of ethanol, and the selectivity of ethnaol production relative to ether production?
In: Chemistry
Describe Le Chatelier's principle and discuss how it can be used to understand the problem created when Flint changed their treated water source from Lake Huron to the Flint River.
In: Chemistry
In an experiment, 11.5 grams of NO2 gas are placed in a container at 30.00°C and 1.26 atm. What is the density of the gas?
In: Chemistry
A monoprotic acid with a Ka of 7.79E10-5 has a partition coefficient of 3.4 (favoring octanol) when distributed between water and octanol. Find the formal concentration of the acid in each phase when 100 mL of 0.10 M aqueous acid is extracted with 31 mL of octanol at (a) pH 4.00 and (b) pH 9.00.
In: Chemistry
an explanation of why oxygen binding proteins like myoglobin and hemoglobin contain heme prosthetic groups, and how the protein structure surrounding the heme affects the relative affinity for oxygen vs. carbon monoxide.
In: Chemistry
A swimming pool in the neighborhood of a smelter receives atmospheric SO2 deposition. The average concentration over the pool is 300 micrograms SO2/m3. If SO2 deposition velocity is 1.2 cm/sec and all SO2 deposited on the pool is transformed to H2SO4,how much NaOH must be added to the pool (moles per square meter of surface area) weekly to neutralize the H2SO4 and prevent the pool from becoming acidified?
In: Chemistry
Write the balanced neutralization reaction between H2SO4 and KOH in aqueous solution. Phases are optional.
0.450 L of 0.490 M H2SO4 is mixed with 0.400 L of 0.210 M KOH. What concentration of sulfuric acid remains after neutralization?
In: Chemistry
How do you write molecular formulas for compounds? How do you identify if they are ionic or covalent? Please use the following as examples: Copper (I) sulfide / Sulfer tetrafluoride
In: Chemistry
Hydrobromic acid dissolves solid iron according to the following
reaction:
Fe(s)+2HBr(aq)?FeBr2(aq)+H2(g)
What mass of HBr (in g) would you need to dissolve a 3.0?g pure iron bar on a padlock? Express your answer using two significant figures. m=______________g
What mass of H2 would be produced by the complete reaction of the iron bar?
Express your answer using two significant figures. m=_____________________g
In: Chemistry
A beaker containing 50.0 mL of 0.300 M Ca2+ at pH 9 is titrated with 0.150 M EDTA. The pCa2+ at the equivalence point is
In: Chemistry