|
A solution contains 10.10 gg of unknown compound dissolved in 50.0 mLmL of water. (Assume a density of 1.00 g/mLg/mL for water.) The freezing point of the solution is -6.05 ∘C∘C. The mass percent composition of the compound is 38.70% CC, 9.74% HH, and the rest is OO. |
Part A What is the molecular formula of the compound? Express your answer as a molecular formula.
|
In: Chemistry
A student carried out reactions A through D as designed in Table 1 in your electronic lab manual, plotted log(rate) vs. log(I-) in EXCEL, and the linear regression yielded the following equation: y = 2..732x-1.032; and the plot of log(rate ) vs. log [IO3-] yield y = 1.368x-1.674.
The order for I- is?
The order for IO3- is?
In: Chemistry
Question #2 (5 pts): Compare the G proteins that acts in transducing the signal from b-adrenergic receptors, and Ras. What properties do they share? How do they differ? What is the functional difference between Gas and Gai?
In: Chemistry
Pick a number between 100 and 1000. For that energy in kJ/mol, what are the associated wavelength (nm), frequency (1/s = Hz) and wavenumber (cm-1)?
In: Chemistry
Hydrogen gas is used as a fuel instead of fossil fuels. Storage of hydrogen is a challenge. One avenue of research involves chemical storage such as incorporating hydrogen as part of a metal hydride. In the following reaction sodium borohydride, NaBH4, is used as a means for storing and later generating the hydrogen gas in situ where it is needed as a fuel. Application of heat and use of a catalyst drives the reaction forward. NaBH4(s) + 2 H2O(l) → NaBO2(s) + 4 H2(g) To test the efficiency of the reaction, 0.11 g of sodium borohydride is catalytically decomposed and 244 mL of hydrogen gas is collected over water at 30.0 °C under an atmospheric pressure of 752 mmHg. Calculate the % yield of the reaction
In: Chemistry
The following reaction is first order in N2O5:
N2O5(g)?NO3(g)+NO2(g)
The rate constant for the reaction at a certain temperature is 0.053/s.
A)
Calculate the rate of the reaction when [N2O5]= 5.4
In: Chemistry
which of the following is a process with a negative S?
In: Chemistry
A solution of a specific vitamin has λmax = 287 nm and a concentration of 8.76 × 10-7 M. The absorbance of the solution at 287 nm is A = 0.190. What is the molar absorptivity of the vitamin at 287 nm? (sample pathlength = 1.00 cm)
In: Chemistry
pls answer 1-4 I would like to check with my answer
1) Saponification of triglycerides gives glycerol and fatty acid salts as shown in the equation below. The groups R1, R2 and R3 represent hydrocarbon chains that may be the same or different.
Saponification is actually a hydrolysis reaction. Explain what a hydrolysis reaction is and the role of sodium hydroxide in this process.
2)The over-the-counter drug Ibuprofen is a 1:1 mixture of R and S isomers of the compound 2-(4-isobutylphenyl)propanoic acid. The two compounds have identical physical properties, but only the S isomer has drug activity. Explain the structural difference between these isomers that accounts for these observations.
3) Halogenation of alkanes in the presence of light is an example of an organic reaction that occurs via free radical intermediates.One example of this is the reaction between methane and chlorine shown in the equations below. Free radical reactions occur in a series of steps called Initiation, Propagation and Termination. Write equations to show an example of each of these steps in the reaction of methane with chlorine in the presence of light.
Initiation reaction (1 mark)
Propagation reaction (1 mark)
Termination reaction (1 mark)
4) The preparation of ethoxybenzene from the reaction between sodium phenoxide and bromoethane is shown in the equation below. Like most organic reactions, this can be described as an interaction between an electron rich species (nucleophile) and an electron deficient species (electrophile).
a) Examine the equation and clearly label each reactant as the nucleophile or electrophile as appropriate.
b) Write an equation to show how sodium phenoxide could be prepared from phenol (hydroxybenzene).
In: Chemistry
Describe the characteristic chemical step that occurs during covalent catalysis. Which four different types of catalytic mechanisms did we discuss to hydrolyze peptide bonds in proteins?
In: Chemistry
Write the balanced net ionic equation for the reaction that occurs in the following case: Cr2(SO4)3(aq)+(NH4)2CO3(aq)→ Part b. Identify the spectator ions in this reaction
In: Chemistry
9) for the reaction
[ 2Al + 3H2SO4 → Al2(SO4)3 + 3 H2SO4] 6.0 g of Al (MW=26.98 g/mol)
are added to 12.0 mL of 0.20 M of H2SO4
A) what is the limiting reagent in the above reaction?
b) how many miles of H2SO4 will be formed?
c) how many grams of Al2(SO4)3 (MW=342.15 g/mol) are produced in the reaction?
In: Chemistry
Consider a buffer made by adding 132.8 g of NaC₇H₅O₂ to 300.0 mL of 2.15 M HC₇H₅O₂ (Ka = 6.3 x 10⁻⁵) What is the pH of the buffer after 0.750 mol of H⁺ have been added?
In: Chemistry
Methanol is prepared industrially from synthesis gas (CO and H2). CO(g) + 2H2(g) ⇌ CH3OH(g); ΔH° = -21.7 kcal Would the fraction of methanol obtained at equilibrium be increased by raising the temperature? Explain.
In: Chemistry