Q1: List three variables you could change to improve the effectiveness of the fractional distillation to separating the ethanol from water?
Q2: Why is 200 proof ethanol not food grade while 190 proof one is?
In: Chemistry
Phosphorus exists as several allotropes that have varying properties. The enthalpy of transition from white P to red P, ΔtransH, is -18 kJ/mol. The densities of white and red phosphorus are 1.823 and 2.270 g/cm3, respectively. At what temperature does white phosphorus become the stable phase at 625 atm of pressure? Assume the formula for phosphorus is P4.
In: Chemistry
which of the following atoms has the largest
ionization energy? O, Li, N, Be or K
In: Chemistry
Make a flow chart for the synthesis of Benzoic Acid from phenyl magnesium bromide and carbon dioxide. Using your knowledge of the physical properties of the solvents, reactants, and products, show how the products can be purified. Indicate which layer should contain the product in the liquid/liquid extraction steps.
In: Chemistry
Do the following problem by hand using TI30Xa calculator. Do the
problem on a fresh sheet of paper (college ruled, printer paper or
engineering paper). Find the decrease in pressure expected in an
NFL football if it was inflated in a room at 80oF, left in the room
for a while, and brought to field at 40oF, and left there for a
while. Use the ideal gas law to find the decrease in pressure as a
number in psi. The ideal gas law is given by
pv = RT where p is the pressure,
v is the specific volume, R is the universal gas
constant, and
T is the absolute temperature. If any numbers for
variables are needed, go to your favorite internet source or books.
You should seek the least numbers needed
**NOTE: Assume specific volume remains constant. If this is the
case how will you solve the problem? What formulas you will
use?
In: Chemistry
Find the pH during the titration of 20.00 mL of 0.1590 M nitrous acid, HNO2 (Ka = 7.1 ✕ 10-4), with 0.1590 M NaOH solution after the following additions of titrant. (a) 0 mL (b) 10.00 mL (c) 15.00 mL (d) 19.00 mL (e) 19.95 mL (f) 20.00 mL (g) 20.05 mL (h) 25.00 mL
In: Chemistry
The leaves of the rhubarb plant contain high concentration of diprotic oxalic acid (HOOCCOOH) and must be removed before the stems are used to make the rhubarb pie. If pKa1=1.23 and pKa2=4.19, what is the pH of a 0.0330 M solution of oxalic acid?
In: Chemistry
A 100.0-mL sample of 0.2 M (CH3)3N (Kb = 5.28 × 10–5) is titrated with 0.2 M HCl. What is the pH at the equivalence point?
In: Chemistry
What is the pH at the equivalence point of the titration of a strong acid with a strong base?
In: Chemistry
Calculate the vibrational energy difference, in cm-1, between the v=0 and v=1 energy level in a hydrogen chloride-35 molecule. Isotope masses to three decimal places are taken from NIST and force constants from hyperphysics. Use the isotope mass, not the average mass.
In: Chemistry
Two structures of alanine can be drawn that have a net charge of zero, but the predominant form of alanine at its pI is zwitterionic. Why is alanine predominantly zwitterionic rather than completely uncharged at its pI? What percent (to one significant figure) of alanine molecules would be in the completely uncharged form at the pI? Hint: pK1 of alanine is 2.35 and pK2 is 9.87.
In: Chemistry
A) A 29.0 mL sample of 0.274 M
methylamine,
CH3NH2, is titrated with
0.238 M hydroiodic acid.
The pH before the addition of any hydroiodic acid
is ______.
B) A 24.5 mL sample of 0.220 M
ethylamine,
C2H5NH2, is
titrated with 0.399 M hydroiodic
acid.
At the titration midpoint, the pH is ______.
C) A 28.2 mL sample of 0.293 M
dimethylamine,
(CH3)2NH, is titrated with
0.273 M hydrochloric acid.
After adding 13.6 mL of hydrochloric
acid, the pH is ______.
In: Chemistry
Calculate the concentration of all species in a 0.150 M solution of H2CO3. H2CO3], [HCO−3], [CO2−3], [H3O+], [OH−] = Enter your answers numerically separated by commas. Express your answer using two significant figures.
In: Chemistry
Explain precipitate hardening clearly ? Feel free to use a binary phase diagram to illustrate how it is accomplished. Explain how precipitate hardening makes a material stronger and harder ? There are two reasons and only one is pinning of dislocations ?
Please type your answer!!! Thanks
In: Chemistry
Part A
Calculate the molar solubility of Ni(OH)2 when buffered at pH=8.0.
Express your answer using one significant figure.
Part B
Calculate the molar solubility of Ni(OH)2 when buffered at pH = 10.3.
Express your answer using one significant figure.
Part C
Calculate the molar solubility of Ni(OH)2 when buffered at pH = 12.0.
Express your answer using one significant figure.
In: Chemistry