A 0.1276−g sample of a monoprotic acid (molar mass = 1.10 × 102
g/mol) was dissolved in 25.0 mL of water and titrated with 0.0633 M
NaOH. After 10.0 mL of base had been added, the pH was determined
to be 4.87. What is the Ka for the acid? Answer in scientific
notation.
Part #1:
30.0 g of glucose (C6H12O6, molar mass = 180.16 g/mol) are
dissolved in 100. grams of water (molar mass 18.02). What is the
mole fraction of water in solution? Note: glucose is a non-volatile
solute.
Part #2:
At 25.0 oC, pure water has a vapor pressure of 24.2 torr. What
would the vapor pressure of the solution in part one be (in
torr)?
Part #3:
A liquid is a mixture of benzene and toluene. The sample
contains 0.225...
20.26 grams of unknown
1
(with molar mass 203.67 g/mol) was dissolved in 182.7 mL of
ethylene glycol in a calorimeter. What change in temperature would
the solution experience as a result of this dissolution? Assume the
solution has the same specific heat capacity as pure ethylene
glycol. The density of ethylene glycol is 1.11
g/cm3.
The ∆Hdissolution
for
unknown 2
is 124.1 kJ/mol
unknown 1.
Chem Question - Gases
Molar Mass N = 14.01 g/mol
Molar Mass H2O = 18.016 g/mol
Vapor Pressure of Water at 25 C is 23.76 torr
Vapor Pressure of Water at 65 C is 187.54 torr
(Show all work and calculations, include units in
answer. If calculations must be used in several parts, rounding
should be made to 6 decimal points to ensure accuracy. Final
Answers can be rounded to 3 decimal points.)
A syringe filled with air can be...
Determine the molarity when 12.9 grams of ethanol,
C2H5OH (Molar mass = 46.08 g/mol) is
dissolved in 248.8-mL of solution. Answer to 2 decimal places.
Determine the molality when 4.93 moles of ethanol are dissolved
in 0.489 kg of water. Answer to 2 decimal places.
Determine the molality of a solution when 43.4 grams of ethanol,
C2H5OH (Molar mass = 46.08 g/mol) is
dissolved in 0.189 kg of water. Answer to 2 decimal places.
Determine the molality when 24.3 grams...
A
mass of 14.22g of (NH4)2SO4 (molar mass = 132.06g/mol) is dissolved
in water. After the solution is heated, 30.19g of Al2(SO4)3•18H2O
(molar mass = 666.36g/mol) is added. calculate the theoretical
yield of the resulting alum. Hint: This is a limiting reactant
problem.
Ethanol, C2H5OH (molar mass = 46 g/mol) is mixed with methanol,
CH3OH (molar mass = 32 g/mol) to make an ideal solution at a given
temperature. If 5.00 g of ethanol and methanol are mixed, what is
the resulting vapor pressure of the solution? (the vapor pressure
at the same temperature for pure ethanol is 44.5 mm Hg and pure
methanol is 88.7 mm Hg)
What mass of a weak acid with a molar mass of 100 g/mol is
necessary to neutralize 25 ml of 0.10 M NaOH solution?
What is the pH of 0.15 g of sodium acetate NaC2H3O2 in 100 ml
water H2O?
A compound has a molar mass of 100 g/mol and the percent
composition (by mass) of 65.45% C, 5.45% H, and 29.09% O. Determine
the empirical formula and the molecular formula.
A 0.520 g sample of a diprotic acid with a molar mass of 255.8
g/mol is dissolved in water to a total volume of 23.0 mL . The
solution is then titrated with a saturated calcium hydroxide
solution.
a. Assuming that the pKa values for each ionization step are
sufficiently different to see two equivalence points, determine the
volume of added base for the first and second equivalence
points.
b. The pH after adding 23.0 mL of the base was...