The answer is B, but I really need a detailed explanation for this.
Equal volumes of the following pairs of solutions are mixed. Which pair will produce a buffer solution?
A. 0.10 mol L-1 HCl and 0.05 mol L-1 NaOH
B. 0.10 mol L-1 HCl and 0.15 mol L-1 NH3
C. 0.10 mol L-1 HCl and 0.05 mol L-1 NH3
D. 0.10 mol L-1 HCl and 0.20 mol L-1 CH3COOH
E. 0.10 mol L-1 HCl and 0.20 mol L-1 NaCl
In: Chemistry
Hi, I need the Lewis Structure, the Molecular Geometry, and polarity of these compounds:
CH2Cl2
BH3
PH3
SF4
PCl5
Thank you very much
In: Chemistry
How do you make a 10, 20, and 30% solution of sucrose?
b. A student measured out 0.509g of galactose and dissolved it in 25.0mL of water. 10.0 cm of sample was added to the cell, producing an angle of 204.4. If the blank's angle was 202.7, what is the observed angle of rotation for the sugar solution, the specific rotation of the sugar, and the percent difference.
c. Calculate the concentration of sucrose using the following information: blank's angle = 180.0, sample height = 9.7cm, and sample's angle = 186.3.
In: Chemistry
True or False
a. a buffer consists of any acid and any base mixed together
b. proteins tend to precipitate at high salt concentration
c. Coulomb's law measures the standard reduction potential between charged molecules
d. A compound with a large dipole moment will be non polar
e. beta mercaptoethanol and performic acid are used to reduce disulfide bonds
f. water has a high heat capacity and a high dialectric constant
g. biomolecules with a chiral center will exist in the body as a racemic mixture
h. alanine is a zwitterion at pH 7.0
i . free protons are never observed in aqueous systems
j. electrophoresis seperates molecules based upon partitioning between a mobile and stationary phase
In: Chemistry
A sample of propane gas (C3H8) having volume of 1.80L at 25oC and 1.65atm was mixed with a sample of oxygen gas having a volume of 35.0L at 31oC and 1.25atm. The mixture was ignited to form carbon dioxide and water. Write the balanced reaction. What is the limiting reagent? What is the maximum number of grams of water which can form from this reaction? Find the number of moles of excess reactant at STP.
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Consider each of the following systems for long times, at which their behacioor is time invariant. Identify each system as equilibrium or steady state.
1) A hose supplies water at a constant rate to a bucket with a hole in it. A constant water level is maintained
2)A mixture of reacting gas molecules is constrained to a fixed temperature, e.g., H2, O2 and H2O at 600 K.
3) Ice floats in water, thermally insulated from its surroundings.
4) Molten steel is poured into a continuous casting mill while withdrawing solid steel from the bottom.
(5) A foil birthday balloon is brought into a hot room.
In: Chemistry
Assuming you have 0.075 grams of benzoic acid in 1 mL of water
A) Calculate the moles of benzoic acid.
B) Assuming you used 1 mL of 2 M NaOH calculate the moles of NaOH present in solution.
C) Is the amount of NaOH sufficient to react with all of the benzoic acid?
In: Chemistry
Complete and balance each of the following equations for combustion reactions.
Express your answer as a chemical equation. Identify all of the phases in your answer.
A. C4H6(g)+O2(g)?
B. C(s)+O2(g)?
C. CS2(s)+O2(g)?
D. CH4O(l)+O2(g)?
In: Chemistry
1. Calculate the molar amount of KHP used to neutralize the NaOH solution.
2. Calculate the molar concentration of the NaOH solution that you prepared.
3. Compare the actual molarity of your NaOH solution with your goal of 0.10 M.
Equivalance point-25.3,
Measurements found in lab.
| Mass of NaOH needed=0.40g | |
| Mass of KHP needed=0.505g | |
In: Chemistry
Consider three hydrocarbon compounds: ethane, CH3CH3; ethene, CH2CH2; and
ethyne, CHCH, in all of which the two carbon atoms are bonded to each other. Of the three, ethyne has the _____________ carbon-carbon bond.
A. longest and strongest B. shortest and weakest
C. shortest and strongest D. longest and weakest
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Molarity of standard NaOH solution: x/1 H 2/3 Unknown + 2/3 NaOH -> 2/3 H2O +Na 2/3 Acetate
| Vinegar: | Titration 1 | Titration 2 | Tirtration 3 |
| Initial V of Acid | .01 mL | 5.56 mL | 11.32 mL |
| Final V of Acid | 5.56 mL | 10.71 mL | 16.02 mL |
| Inital V of Base | .01 mL | 27.12 mL | 3.01 mL |
| Final V of Base | 22.23 mL | 44.71 mL | 24.90 mL |
Unknown Acid code and number of reactive hydrogens: H+3
| Unknown Acid | Titration 1 | Titration 2 (Error) | Titration 3 | Titration 4 |
| Mass of Acid | .1024 g | .1028g | .1021g | .1023g |
| Initial V of Base | 24.90 mL | 37.80 mL | 45.5 mL | 9.24 mL |
| Final V of Base | 37.80 mL | 45.5 mL | 9.24 mL | 17.80 mL |
10. Find the moles of base (NaOH) for each of your unknown acid titrations.
11. Find the balanced equation using the number of reactive hydrogens (call an acid with one reactive hydrogen HA, one with two reactive hydrogens H2A, and so on).
12. Find the moles of unknown acid for each of your three unknown acid solutions.
13. Use the mass of unknown acid and the moles of unknown acid to find the formula mass of your unknown acid for each of your three unknown acid titrations.
In: Chemistry
Rank the relative acid strengths of the following compounds: H2O, H2S, and H2Se
___ > ___ > ___
In: Chemistry
Leachate is produced when precipitation infiltrates a sanitary landfill,
contacts the waste material, and appears at the bottom of the stored waste. Assume 6.9 kg of
benzene
(C 6 H 6 ) were placed in the landfill and it is all dissolved in the 90,000 gallons of leachate produced
during 1 year. What is the benzene concentration in the leachate during this 1 year in (a) mg/L, (b)
ppb m and (c) moles/L?
In: Chemistry
a)Calculate the equilibrium constant at 10 K for a reaction with ΔHo = 10 kJ and ΔSo = 100 J/K.
b) Calculate the equilibrium constant at 105 K for the thermodynamic data in the previous question.
In: Chemistry
1000 m3 of moist air at 101 kPa and 25 °C with a dew point of 11 °C enters a process. The air leaves the process at 98 kPa with a dew point of 58 °C. Assume ideal gases.
(a) Draw and label a flowsheet for the process.
b) What is the mole fraction of water in the air entering the process? Leaving the process?
(c) How many moles of water are added to or removed from the 1000 m3 of moist air?
In: Chemistry