1) A sample of gas in a balloon has an initial temperature of 45C and a volume of 1.28×103 L . If the temperature changes to 62C , and there is no change of pressure or amount of gas, what is the new volume, V2 of the gas?
V2=?
2) What Celsius temperature T2, is required to change the volume of the gas sample in Part A (T1=45C, V1=1.28×103 L) to a volume of 2.56×103 LL ? Assume no change in pressure or the amount of gas in the balloon.
T2=?
In: Chemistry
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A 110.0 mL buffer solution is 0.110 molL−1 in NH3 and 0.125 molL−1 in NH4Br. |
Part A (PLEASE ANSWER EVERY PART CORRECTLY :)) What mass of HCl will this buffer neutralize before the pH falls below 9.00? (Kb(NH3)=1.76×10−5 Express your answer using two significant figures.
Part B If the same volume of the buffer were 0.265 molL−1 in NH3 and 0.390 molL−1 in NH4Br, what mass of HCl could be handled before the pH fell below 9.00? Express your answer using two significant figures.
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In: Chemistry
Classify each of the following reactions as one of these four types:
• spontaneous at all temperatures • not spontaneous at any temperature • spontaneous below a certain temperature but not above
• spontaneous above a certain temperature but not below
(a) PbS (s) + Mg (s) → Mg (s) + Pb (s); ∆H = 66 kJ; ∆S = -9 J/K
(b) 2 SO2 (g) + O2 (g) → 2 SO3 (g); ∆H = -197.8 kJ; ∆S = -188.1 J/K
(c) 2 N2O (g) + O2 (g) → 4 NO (g); ∆H = 199.5 kJ; ∆S = 198.2 J/K
(d) 2 C8H18 (l) + 25 O2 (g) → 16 CO2 (g) + 18 H2O (g); ∆H = -10139 kJ; ∆S = 977 J/K
In: Chemistry
calculate the ph of 1.0 l of a buffer that is .01 m of HNO2 and .15 m NaO2. what is the ph of the same buffer and after the additon of 1.0 l of 12m hcl (pka of HNO2 is 3.4)
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A sample of granite at 85.0 C is immersed into a 75.0g of water at 24.0C. At equilibrium the temp. is 28.7C, what is the mass of the granite? (Cs for granite=.790 J/g*C)
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If at 30F the air has 25% relative humidity, what is the relative humidity at 70F and how much moisture must be added to get it up to 50% relative humidity.
In: Chemistry
Arrange the following reaction in order of increasing S value.
1. H2(g) + F2(g) 2HF(g)
2. NH4NO3(s) N2O(g) + 2H2O(I)
3. (NH4)2 Cr2O7(s) Cr2O3(s) + 4H2O(I) +N2(g)
In: Chemistry
How do 'coupled reactions' allow life (as a biochemical process) to exist?
In: Chemistry
A) How many grams of solid sodium
fluoride should be added to 2.00
L of a 0.190 M hydrofluoric acid
solution to prepare a buffer with a pH of 2.425
?
grams sodium fluoride = g.
B) How many grams of solid sodium
fluoride should be added to 1.00
L of a 0.299 M hydrofluoric acid
solution to prepare a buffer with a pH of 3.825
?
grams sodium fluoride = g.
C) How many grams of solid ammonium
bromide should be added to 1.00 L
of a 9.88×10-2 M
ammonia solution to prepare a buffer with a pH of
10.080?
grams ammonium bromide = g.
In: Chemistry
I was analyzing the sample in Agilent HPLC
and I got 3 peaks at 3.654min, 4.540min and 7.839min with 0.1175, 0.1366 and 0.1571 width values
anyone knows how to calculate N value (#of plates), retention factor, selectivity factor and resolution value for this chromatograms?
In: Chemistry
1. How would the reaction be affected if bromoethane were used instead of iodoethane?
2. How would the reaction be affected if 2-iodopropane were used instead of iodoethane?
experiment: http://legacy.earlham.edu/~seuka/Biochemistry/Ex.%2007%20Saccharin%20Alkylation.pdf
In: Chemistry
what is the new PH of a solution if 10ml of 0.1 M Hcl is added to 150ml of a buffer system that is 0.1M Benzoic acid and 0.1M sodium benzoate ( the Ka of benzoic acid is 6.3X10^-5). Thanks
In: Chemistry
In: Chemistry
In the reaction where cyclohexanol is put into a round bottomflask with phosphoric acid and sulfuric acid and heated in a fractional distillation system, why is it important to use a round bottom flask that fits tightly onto the distillation apparatus as th reciever. Why is it then cooled in an ice bath?
In: Chemistry
A 0.4569 g sample of pewter, containing tin, lead, copper, and zinc, was dissolved in acid. Tin was precipitated as SnO2·4H2O and removed by filtration. The resulting filtrate and washings were diluted to a total volume of 250.0 mL. A 20.00 mL aliquot of this solution was buffered, and titration of the lead, copper, and zinc in solution required 34.02 mL of 0.001513 M EDTA. Thiosulfate was used to mask the copper in a second 25.00 mL aliquot. Titration of the lead and zinc in this aliquot required 34.42 mL of the EDTA solution. Finally, cyanide was used to mask the copper and the zinc in a third 30.00 mL aliquot. Titration of the lead in this aliquot required 25.92 mL of the EDTA solution. Determine the percent composition by mass of each metal in the pewter sample.
In: Chemistry