OC userin ChemistryΒ·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 PhysicsΒ·9 Nov 201714.8. In a physics lab, you attach a 0.200-kg air-track glider to the end of an ideal spring of negligible mass and start it oscillating. The elapsed time from when the glider first moves through the equilibrium point to the second time it moves through that point is 2.60 s. Find the spring's force constant.
OC userin ChemistryΒ·8 Nov 201739. Give each ionic compound an appropriate name. a. Sno b. Cr,S3 C. RbI d. BaBr2
OC userin ChemistryΒ·10 Nov 2017104. Consider the reaction shown here occurring at 25Β°C. Cr(s) + Cd2+(aq) β 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 PhysicsΒ·8 Nov 201731.11 - A 0.180-H inductor is connected in series with a 90.0-12 resistor and an ac source. The voltage across the inductor is v. = -(12.0 V)sin((480 rad/s)t]. a) Derive an expression for the voltage Ur across the resistor. (b) What is up at t = 2.00 ms?
OC userin ChemistryΒ·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 Β°C. Is the combustion of methanol spontaneous?
OC userin PhysicsΒ·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 ChemistryΒ·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 ChemistryΒ·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 ChemistryΒ·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 ChemistryΒ·9 Nov 201721. What is the structure of benzene? What are the different ways in which this structure is represented?
OC userin PhysicsΒ·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 ChemistryΒ·7 Nov 2017Q7. Use Table 19.1 to calculate AGΒΊ for the reaction. 2 MnO4 (aq) + Ca(s) β 2 MnO,- (aq) + Cd2+(aq) a) +30.9 kJ b) -30.9 kJC) -185 kJ d) +185 kJ
OC userin ChemistryΒ·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 ChemistryΒ·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?