OC userin Chemistry·7 Nov 201759. Methanol (CH3OH) burns in oxygen to form carbon dioxide and water. Write a balanced equation for the combustion of liq- uid methanol and calculate AHIX, A Sex, and A Gixnat 25 °C. Is the combustion of methanol spontaneous?
OC userin Physics·9 Nov 20172.36 A small rock is thrown vertically upward with a speed of 22.0 m/s from the edge of the roof of a 30.0-m-tall building. The rock doesn't hit the building on its way back down and lands on the street below. Ignore air resistance. (a) What is the speed of the rock just before it hits the street? (b) How much time elapses from when the rock is thrown until it hits the street?
OC userin Chemistry·9 Nov 2017104. Predict whether a precipitate will form if you mix 175.0 mL of a 0.0055 M KCl solution with 145.0 mL of a 0.0015 M AgNO3 solution. Identify the precipitate, if any.
OC userin Chemistry·7 Nov 201729. How much time (in seconds) does it take light in a vacuum to travel 1.00 billion km? a) 3.00 x 1017 b) 3.33 s c) 3.33 x 10's d) 3.00 x 1020
OC userin Chemistry·6 Nov 201763. The rate constant (k) for a reaction was measured as a function of temperature. A plot of In k versus 1/T in K) is linear and has a slope of -7445 K. Calculate the activation energy for the reac- tion.
OC userin Chemistry·9 Nov 201721. What is the structure of benzene? What are the different ways in which this structure is represented?
OC userin Physics·8 Nov 201787. Calculate the number of atoms in each sample. a. 5.18 g P b . 2.26 g Hg c. 1.87 g Bid. 0.082 g Sr
OC userin Chemistry·7 Nov 2017Q7. Use Table 19.1 to calculate AGº for the reaction. 2 MnO4 (aq) + Ca(s) — 2 MnO,- (aq) + Cd2+(aq) a) +30.9 kJ b) -30.9 kJC) -185 kJ d) +185 kJ
OC userin Chemistry·7 Nov 2017113. A friend wants you to invest in a new battery she has designed that produces 24 V in a single voltaic cell. Why should you be wary of investing in such a battery?
OC userin Chemistry·5 Nov 201710. Describe Rutherford's gold foil experiment. How did the experi- ment prove that the plum-pudding model of the atom was wrong?
OC userin Chemistry·7 Nov 2017101. This reaction has an activation energy of zero in the gas phase: CH3 + CH3 -C2H5 a. Would you expect the rate of this reaction to change very much with temperature? b. Why might the activation energy be zero? c. What other types of reactions would you expect to have little or no activation energy?
OC userin Chemistry·7 Nov 2017Contains Verified AnswerQ6. Which combination is the best choice to prepare a buffer with a pH of 9.0? a) NH3; NH4Cl (pKb for NH3 is 4.75) b) C5H3N; C3H5NHCl (pKb for CsH3N is 8.76) c) HNO2; NaNO2 (pK, for HNO2 is 3.33) d) HCHO2; NaCHO2 (pK, for HCHO, is 3.74)
OC userin Chemistry·4 Nov 201731. Calculate the percent ionization of a 0.15 M benzoic acid solu- tion in pure water and in a solution containing 0.10 M sodium benzoate. Why does the percent ionization differ significantly in the two solutions?
OC userin Physics·5 Nov 20171.3. How many nanoseconds does it take light to travel 1.00 ft in vacuum? (This result is a useful quantity to remember.)
OC userin Chemistry·6 Nov 201735. The distance from the sun to Earth is 1.496 X 108 km. How long does it take light to travel from the sun to Earth?