OC userin Chemistry·15 Nov 201725. Consider the reaction: 2 HBr(8) — H2(g) + Brz(8) a. Express the rate of the reaction in terms of the change in concentration of each of the reactants and products. b. In the first 25.0 s of this reaction, the concentration of HBr dropped from 0.600 M to 0.512 M. Calculate the average rate of the reaction during this time interval. c. If the volume of the reaction vessel in part b was 1.50 L, what amount of Brz (in moles) was formed during the first 15.0 s of the reaction?
OC userin Chemistry·14 Nov 2017Q3. Which idea came out of Rutherford's gold foil experiment? a) Atoms contain protons and neutrons. b) Matter is composed of atoms. c) Elements have isotopes. d) Atoms are mostly empty space.
OC userin Chemistry·12 Nov 201769. What are the products of each aromatic substitution reaction? H H + Br2 FeBry febrer CH3 + CH3-CH-a Ald;
OC userin Chemistry·13 Nov 2017121. A 0.25-mol sample of a weak acid with an unknown pk, was combined with 10.0 mL of 3.00 M KOH, and the resulting solu- tion was diluted to 1.500 L. The measured pH of the solution was 3.85. What is the pKof the weak acid?
OC userin Chemistry·13 Nov 201758. Which buffer system is the best choice to create a buffer with pH = 9.00? For the best system, calculate the ratio of the masses of the buffer components required to make the buffer. HF/KF HNO2/KNO2 NH3/NH4Cl HCIO/KCIO
OC userin Chemistry·10 Nov 201794. The solubility of copper(I) chloride is 3.91 mg per 100.0 mL of solution. Calculate Ksp for CuCl.
OC userin Chemistry·10 Nov 201715. Explain how a chemical reaction occurs according to the coll- sion model. Explain the meaning of the orientation factor in this model.
OC userin Chemistry·11 Nov 2017125. Use the concepts in this chapter to obtain an estimate for the number of atoms in the universe. Make the following assump- tions: (a) All of the atoms in the universe are hydrogen atoms in stars. (This is not a ridiculous assumption because over three-fourths of the atoms in the universe are in fact hydrogen. Gas and dust between the stars represent only about 15% of the visible matter of our galaxy, and planets compose a far tinier fraction.) (b) The sun is a typical star composed of pure hydro- gen with a density of 1.4 g/cm and a radius of 7 x 108 m. (c) Each of the roughly 100 billion stars in the Milky Way gal axy contains the same number of atoms as our sun. (d) Each of the 10 billion galaxies in the visible universe contains the same number of atoms as our Milky Way galaxy.
OC userin Chemistry·9 Nov 201776. Consider the reaction: 12(g) + Cl2(g) = 2 ICI(g) Kp = 81.9 at 25°C Calculate AGxn for the reaction at 25°C under each of the following conditions: a. standard conditions b. at equilibrium c. Pa = 2.55 atm; R = 0.325 atm; Pa, = 0.221 atm
OC userin Chemistry·9 Nov 20175. What is the pH of a buffer solution when the concentrations of both buffer components (the weak acid and its conjugate base) are equal? What happens to the pH when the buffer contains more of the weak acid than the conjugate base? More of the con- jugate base than the weak acid?
OC userin Chemistry·8 Nov 201739. Give each ionic compound an appropriate name. a. Sno b. Cr,S3 C. RbI d. BaBr2
OC userin Chemistry·10 Nov 2017104. Consider the reaction shown here occurring at 25°C. Cr(s) + Cd2+(aq) — Cr2+(aq) + Cd(s) Determine Ecell, K, and AGxn for the reaction and complete the table. [Cd2+1 [Cr2+1 Q Ecoll A Grxn 1.00 1.00 1.00 x 10-5 1.00 x 10-5 1.00 4.18 x 10-4 1.00 1.00
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 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.