30 grams of steam at 130C are colled to the boiling point, condensed, then cooled to 0C and frozen into ice. What is the total change in entropy of the water? what is the total change in gibbs energy? state any assumptions you are making.
In: Chemistry
The pKb values for the dibasic base B are pKb1 = 2.10 and pKb2 = 7.38. Calculate the pH at each of the following points in the titration of 50.0 mL of a 0.70 M B(aq) with 0.70 M HCl(aq).
(a) before addition of any HCl ____
(b) after addition of 25.0 mL of HCL ____
(c) after addition of 50.0 mL of HCl ____
(d) after addition of 75.0 mL of HCl ____
(e) after addition of 100.0 mL of HCl ____
In: Chemistry
A 25.0 mL aqueous solution contains 500.0 mg of a compound. Calculate the amount of solid extracted by diethyl ether from the solution by each of the following extraction procedures (assume a distribution coefficient (K) of 5.0 for each extraction):
a. A single 15.0 mL extraction with diethyl ether.
b. A single 150.0 mL extraction with diethyl ether.
c. Three sequential 5.0 mL extractions with diethyl ether.
show work please
In: Chemistry
You are interested in determining the heat of isomerization of two isomers (A and B), so you measure their heats of combustion. The difference between the heats of combustion is equal to the heat of isomerization. You are given two separate samples of (1.5 ± 0.1) mol for each isomer, A and B, and they are burned in a constant-pressure calorimeter.
The heat of capacity of the calorimeter is (8.44 ± 0.05) kJ K-1. Combustion of isomer A causes the temperature to rise by (2.0 ± 0.1) K, and isomer B causes the temperature to rise by (3.5 ± 0.1) K.
(a) Calculate the molar heat of isomerization (ΔHi = ΔHB - ΔHA)
(b) Calculate the uncertainty in the molar heat of isomerization. Assume that the errors in the moles of isomers A and B, heat capacity of the calorimeter, and temperature readings are small and independent.
In: Chemistry
What is the pressure (in millimeters of mercury) inside a container of gas connected to a mercury-filled open-end manometer of the sort shown in Figure 9.4 in the textbook when the level in the arm connected to the container is 18.0 cm lower than the level in the arm open to the atmosphere, and the atmospheric pressure reading outside the apparatus is 765.3 mm Hg ?
In: Chemistry
Find the pH of the following solution
10.0mL of solution A (which is .15 of .5M of acetic acid and .15 of .5M of sodium acetate) and 10.0mL of 0.1M of HNO3
10.0mL of solution A (same as above) and 10.0mL of 0.1M of NaOH
In: Chemistry
Perhaps the most central concept in amino acid degradation is that some amino acids are glucogenic, some are ketogenic and some are both glucogenic and ketogenic. Which of the following amino acids is both glucogenic and ketogenic?
A. Arg
B. Ile
C. Leu
D. Asn
E. Cys
In: Chemistry
find the pH of a 40 mL buffer solution + 1.0 mL of 6.0 M HCl (aq)
I know this question is pretty simple, but do I need to know what the buffer is made of? Is it important? if not how would I set up the ICE table? thank you!
In: Chemistry
a) A buffer contains significant amounts of hydrofluoric (HF) and sodium fluoride (NaF). Write the net ionic equation showing how this buffer neutralizes added HNO3. Express your answer as a chemical equation. Identify all of the phases in your answer
b) Write the net ionic equation showing how this buffer neutralizes added KOH. Express your answer as a chemical equation. Identify all of the phases in your answer
In: Chemistry
Devise a synthesis of 5-methyl-1-hexyne using one of the starting materials and any of the reagents below using the fewest steps possible. If you need fewer than the 3 steps allowed, enter "none" for reagents in the remaining unused steps.
Starting Materials:
(1.) HC(triple bonded)CH
(2.) HC(triple bonded)C-CH3
(3.) HC(triple bonded)C-CH2CH3
(4.) HC(triple bonded)C-CH2CH2CH2CH3
(5.) HC(triple bonded)C-CH(CH3)(CH3)
(6.) HC(triple bonded)C-C(CH3)(CH3)(CH3)
Reagents:
a. NaNH2/NH3 (l)
b. NaOH/H2O
c. iodomethane
d. idoethane
e. 1-bromopropane
f. 2-bromopropane
g. 1-bromo-3-methylbutane
h. t-butyl bromide
i. H2/ Pd on Carbon
Answer the following:
Starting Material:
Reagent for step 1:
Reagent for step 2:
Reagent for step 3:
** ALSO, PLEASE ANSWER THE SAME QUESTIONS USING: (Z)-4,4-dimethyl-2-pentene AND (E)-3-octene (Instead of 5-methyl-1-hexyne)
In: Chemistry
How many milliliters of 0.120 M NaOH are required to tritrate 50.0 mL of 0.0998 M hydrochloric acid to the equivale point the Ka of hypochlorous acid is 3.0×10^-8. What is the pH after the NaOH is added?
In: Chemistry
when 1.0 mol of NO(g) forms from its elements, 90.29 kJ of heat is absorbed. How much heat is evolved when 5.40 g of NO decomposes to its elements?
In: Chemistry
A sample of 7.5 L of NH3 gas at 22 ∘C and 735 torr is bubbled into a 0.50-L solution of 0.40 M HCl. Assuming that all the NH3 dissolves and that the volume of the solution remains 0.50 L, calculate the pH of the resulting solution.
In: Chemistry
An aqueous solution of ethyl acetate at room temperature has an itial concentration of 0.15 M. Calculate the equilibrium concentrations of ethyl acetate (CH3COOC2H5), ethanol (C2H5OH) and acetic acid if the equilibrium constant at this temperature is Kc= 3.00. Part B. Repeat this calculation for initial ehtyl acetate concentrations of 0.25 M and 0.35 M. Are your answers in agreement with Le Chatelier's Principle?
In: Chemistry