A rocket took 300 days to travel 780,000,000 km. It carried 200. tons of propellant (density 0.986 g/mL
a) What is this in miles per hour?
b) Express the fule efficiency in miles per gallon.
Please write out the steps needed to calculate this. Thank you.
In: Chemistry
Three different blocks of Al, Cu, and Fe, each of them with a mass of 8.5 g, 4) absorb 0.845 kJ of heat at 25°C. The specific heats of Al, Cu, and Fe are 0.900 J/g·°C, 0.385J/g·°C, and 0.444 J/g·°C, respectively. a) Which block reaches the highest temperature? b) What is that temperature (in oC)?
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The decomposition of N2O5 occurs with a rate constant of 4.3 x 10–3 sec–1 at 65C and 3.0 x 10–5 sec–1 at 25C. What is the activation energy of the process?
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1. Consider the thermodynamics of the hypothetical process
H2O(l) --> ice-nine(s)
Based on the information above, will DG° for the formation of ice-nine from liquid water be positive or negative? Explain how you know.
Will the entropy, S°, for the system (the ocean) increase or decrease for this process? Explain how you know.
Based on your answers above, will the enthalpy change, DH°, for this process be positive or negative? Write a mathematical equation to support your answer.
Based on your answer to part c , will there be a change in the temperature of the ocean and its surroundings as the liquid water is converted to ice-nine? Explain.
Given that the melting point of ice-nine is much higher than that of regular ice, will the H° for the conversion of water to ice-nine be more positive or more negative than the H° for the conversion of water to regular ice? Explain.
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A 1H 127I molecule, with a bond length of 160 pm, absorbed on the surface and rotates in two dimensions. A) Calculate the zero point energy associated with this rotation B) What is the smallest quantum energy that can be absorbed by this molecule in a rotational excitation?
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Calculate the pH for each of the following cases in the titration of 50.0 mL of 0.190 M HClO(aq) with 0.190 M KOH(aq).
a) before addition of any KOH
b) after addition of 25.0 mL of KOH
c) after addition of 35.0 mL of KOH
d) after addition of 50.0 mL of KOH
e) after addition of 60.0 mL of KOH
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A student is working on the separation of a three-compound mixture, consisting of a carboxylic acid, amine, and neutral compound, and starts by extracting the dichloromethane solution of the mixture with 10% NaHCO3 rather than 5% HCl. Assuming the student recognizes the error before proceeding further, would the student still be able to separate and identify the components of the mixture? Describe what changes would have to be made to the remainder of the procedure in order to do so.
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The standard electrode use to reference all electrode potentials to is? A.chlorine/chloride B.Cu2+/copper C.proton/hydrogen D.Zn2+/zinc
In: Chemistry
In: Chemistry
A TLC plate showed two spots of Rf 0.25 and 0.26. The plate was dried carefully, and returned to the developing chamber. What would you expect to see after the second development was complete?
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| Reduction half-reaction | E∘ (V) |
| Ag+(aq)+e−→Ag(s) | 0.80 |
| Cu2+(aq)+2e−→Cu(s) | 0.34 |
| Sn4+(aq)+4e−→Sn(s) | 0.15 |
| 2H+(aq)+2e−→H2(g) | 0 |
| Ni2+(aq)+2e−→Ni(s) | −0.26 |
| Fe2+(aq)+2e−→Fe(s) | −0.45 |
| Zn2+(aq)+2e−→Zn(s) | −0.76 |
| Al3+(aq)+3e−→Al(s) | −1.66 |
| Mg2+(aq)+2e−→Mg(s) | −2.37 |
1)
Use the table of standard reduction potentials given above to calculate the equilibrium constant at standard temperature (25 ∘C) for the following reaction: Fe(s)+Ni2+(aq)→Fe2+(aq)+Ni(s)
2)
Calculate the standard cell potential (E∘) for the reaction
X(s)+Y+(aq)→X+(aq)+Y(s)
if K = 3.80×10−4.
Express your answer to three significant figures and include the appropriate units.
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Consider the following liquid junction cell at room temperature:
Zn(s) / ZnSO4(aq) // CuSO4(aq) / Cu(s)
The left side of the cell contains an electrolyte solution at 9.26*10^-2 M and the right side of the cell contains an electrolyte solution at 7.32*10^-2 M.
Calculate the observed cell potential using the Nernst Equation, the Debye-Huckel Limiting Law, and ionic activities.
In: Chemistry
1. a. What is the pH of a solution formed by combining 50.00 mL of a 0.0855 M acetic acid solution, 25.00 mL of 0.1061 M NaOH solution and 25.00 mL of deionized water? Show your work.
b. What is the pH when the solution in 1a is diluted 1 mL in 10 mL total volume? Show your work.
c. What is the pH when 25.00 mL of the solution in #1a has 5.00 mL of a 0.1056 M HCl solution added to it? Show your work.
c. What is the pH when 25.00 mL of the solution in #1a has 5.00 mL of a 0.1056 M NaOH solution added to it? Show your work.
In: Chemistry
A 500 mL saturated solution of MgCO3 (MM =
84.3 g/mol) is reduced to 120 mL by evaporation. What mass of solid
MgCO3 is formed? Ksp = 4.0 x 10-5
for MgCO3.
EDIT: If ions can evaporate in water then the answer below is
right. If not, this is how I solved the problem.
MgCO3 dissolves at a 1:1 ratio, therefore
Ksp=s2 and s=Ksp1/2 (or
sqrt of Ksp)
s = (4.0x10-5)1/2 = .00632 M
Using the equation M1V1=M2V2
M1 = s = 0.00632; V1 = 0.500; V2 = 0.120
Solving for M2 = 0.0263 M
Then multiply M2 by MM to get the mass.
Therefore, mass = (0.0263)(84.3) = 2.22g
Can anyone confirm this?
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Using ICE tables and acid-base equations, compare the change in pH that occurs when 10 mL of a 0.10 M NaOH is added to 100 mL of pure water, and when it is added to 100 mL of a benzoic acid buffer soltution that is 0.15 M in both C6H5CO2H and C6H5CO2Na. *Hint: M1V1=M2V2
In: Chemistry