An aqueous solution contains 0.352 M
methylamine
(CH3NH2).
How many mL of 0.309 M hydrobromic
acid would have to be added to 150 mL of
this solution in order to prepare a buffer with a pH of
10.600.
In: Chemistry
Which solution has the highest pH?
a. 0.10 M NaF(aq)
b. 0.10 M NaCl(aq)
c. 0.10 M NaBr(aq)
d. 0.10 M NaClO4(aq)
In: Chemistry
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Problem 9.19 Aqueous ammonia is commercially available at a concentration of 16.0 M. |
Part A How much of the concentrated solution would you use to prepare 400.0 mL of a 1.70 M solution?
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In: Chemistry
The equilibrium water vapor pressure table gives the partial pressure of water when the gas is 100.% saturated with water vapor. If the gas you collected was actually only 85% saturated with water vapor, calculate the percent error in the number of moles of N2 collected in Part I.
mass nano2 = .111g
v of wet n2 gas = 37.9 ml
partial pressure n2 = .966 atm
moles n2 collected = 1.53*10^-3
moles n2 expected = 1.61*10^-3
In: Chemistry
Explain the role that conformation angle plays in the mechanical behavior of amorphous polymer materials
Need help with this question. Correct answer will be rated 5 stars
In: Chemistry
Select all of the correct statements about
reaction quotients and equilibrium constants from the choices
below.
A reaction quotient equals the equilibrium constant at
equilibrium.
K changes as temperature changes, but is independent of
concentrations.
If Q = K the reaction is already at equilibrium.
A reaction quotient is the same as an equilibrium constant.
The richer a reaction mixture is in product the higher its Q value
is.
As a reaction approaches equilibrium its Q value rises and its K
value falls until they are equal.
In: Chemistry
a. A 1 liter solution contains 0.509 M
hypochlorous acid and 0.382 M
potassium hypochlorite.
Addition of 0.191 moles of hydroiodic
acid will:
(Assume that the volume does not change upon the addition of
hydroiodic acid.)
Raise the pH slightly
Lower the pH slightly
Raise the pH by several units
Lower the pH by several units
Not change the pH
Exceed the buffer capacity
b. A 1 liter solution contains 0.246 M
hypochlorous acid and 0.328 M
potassium hypochlorite.
Addition of 0.271 moles of sodium
hydroxide will:
(Assume that the volume does not change upon the addition of
sodium hydroxide.)
Raise the pH slightly
Lower the pH slightly
Raise the pH by several units
Lower the pH by several units
Not change the pH
Exceed the buffer capacity
In: Chemistry
Sulfur dioxide and oxygen react exothermically according to the thermochemical equation shown below. Calculate the maximum amount of heat that could be released if 15.0 g of O2 gas is allowed to react with 13.4 L of SO2 gas at 1.00 atm and 15°C. (CAUTION: This problem may not be as simple as it looks. So please think about it before you start working.) 2 SO2(g) + O2(g) → 2 SO3(g) ΔH° = –198 kJ
In: Chemistry
If 2.99 g of sodium peroxide (Na2O2) react
with water to produce sodium hydroxide and oxygen, how many liters
of oxygen will be produced at 30.4 °C and 734 torr?
2 Na2O2(s) + 2 H2O(l) → 4 NaOH(aq) + O2(g)
In: Chemistry
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)
In: Chemistry
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)
In: Chemistry
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