OC userin Physics·31 Oct 201797. The ratio of oxygen to carbon by mass in carbon monoxide is 1.33:1.00. Find the formula of an oxide of carbon in which the ratio by mass of oxygen to carbon is 2.00:1.00.
OC userin Chemistry·1 Nov 2017105. Consider the unbalanced redox reaction: MnO4 (aq) + Zn(s) — Mn2+ (aq) + Zn2+ (aq) Balance the equation and determine the volume of a 0.500 M KMnO4 solution required to completely react with 2.85 g of Zn.
OC userin Chemistry·30 Oct 2017Q6. The Zn/Zn²+ electrode has a standard electrode potential of E = -0.76 V. How does the relative potential energy of an electron at the Zn/Zn2+ electrode compare to the potential energy of an electron at the standard hydrogen electrode? a) An electron at the Zn/Zn2+ electrode has a higher potential energy than an electron at the standard hydrogen electrode. b) An electron at the Zn/Zn2+ electrode has a lower potential energy than an electron at the standard hydrogen electrode. c) An electron at the Zn/Zn2+ electrode has the same potential energy as an electron at the standard hydrogen electrode. d) Nothing can be concluded about the relative potential energy of an electron at the standard electrode potential.
OC userin Chemistry·30 Oct 201738. Sulfur and fluorine form several different compounds including sulfur hexafluoride and sulfur tetrafluoride. Decomposition of a sample of sulfur hexafluoride produces 4.45 g of fluorine and 1.25 g of sulfur, while decomposition of a sample of sulfur tetra- fluoride produces 4.43 g of fluorine and 1.87 g of sulfur. Calcu- late the mass of fluorine per gram of sulfur for each sample and show that these results are consistent with the law of multiple proportions.
OC userin Physics·29 Oct 201711.30. A vertical, solid steel post 25 cm in diameter and 2.50 m long is required to support a load of 8000 kg. You can ignore the weight of the post. What are (a) the stress in the post; (b) the strain in the post; and (c) the change in the post's length when the load is applied?
OC userin Physics·30 Oct 2017Q1.23 Consider the vector products AX (BXC) and (AXB) Xč. Give an example that illustrates the general rule that these two vector products do not have the same magnitude or direction. Can you choose vectors A, B, and such that these two vector products are equal? If so, give an example.
OC userin Accounting·31 Oct 2017EXERCISE 12-14 Identification of Relevant Costs [L012-1] Kristen Lu purchased a used automobile for $8,000 at the beginning of last year and incurred the following operating costs: Depreciation ($8,000 = 5 years) Insurance ..... Garage rent .......... Automobile tax and license ............ Variable operating cost .......... $1,600 $1,200 $360 $40 $0.14 per mile The variable operating cost consists of gasoline, oil, tires, maintenance, and repairs. Kristen esti- mates that, at her current rate of usage, the car will have zero resale value in five years, so the annual straight-line depreciation is $1,600. The car is kept in a garage for a monthly fee. Required: 1. Kristen drove the car 10,000 miles last year. Compute the average cost per mile of owning and operating the car. 2 Kristen is unsure about whether she should use her own car or rent a car to go on an extended cross-country trip for two weeks during spring break. What costs above are relevant in this decision? Explain. 3. Kristen is thinking about buying an expensive sports car to replace the car she bought last year. She would drive the same number of miles regardless of which car she owns and would rent the same parking space. The sports car's variable operating costs would be roughly the same as the variable operating costs of her old car. However, her insurance and automobile tax and license costs would go up. What costs are relevant in estimating the incremental cost of owning the more expensive car? Explain.
OC userin Chemistry·30 Oct 201787. Ethene (C2H4) can be halogenated by the reaction: C2H4(8) + X2(g) = C2H4X2(8) where X2 can be Cl2, Br2, or 12. Use the thermodynamic data given to calculate AH, AS, AG®, and K, for the halogenation reaction by each of the three halogens at 25°C. Which reaction is most spontaneous? Least spontaneous? What is the main fac- tor responsible for the difference in the spontaneity of the three reactions? Does higher temperature make the reactions more spontaneous or less spontaneous? Compound AH; (kJ/mol) Sº (J/mol ·K) 308.0 C2H4Cl2(g) -129.7 +38.3 C2H4Br2(g) C2H412(g) 330.6 347.8 +66.5
OC userin Chemistry·30 Oct 201773. Ultraviolet radiation and radiation of shorter wavelengths can damage biological molecules because these kinds of radiation carry enough energy to break bonds within the molecules. A typical carbon-carbon bond requires 348 kJ/mol to break. What is the longest wavelength of radiation with enough ener gy to break carbon-carbon bonds?
OC userin Chemistry·30 Oct 201756. The fluids within cells are buffered by H2PO4 and HPO42- a. Calculate the ratio of HPO42-to H2PO4 required to main- tain a pH of 7.1 within a cell. b. Could a buffer system employing H3PO4 as the weak acid and H2PO4 as the weak base be used as a buffer system within cells? Explain.
OC userin Physics·30 Oct 201731.25 . A series ac circuit contains a 250-22 resistor, a 15-mH inductor, a 3.5-F capacitor, and an ac power source of voltage amplitude 45 V operating at an angular frequency of 360 rad/S. (a) What is the power factor of this circuit? (b) Find the average power delivered to the entire circuit. (c) What is the average power delivered to the resistor, to the capacitor, and to the inductor?
OC userin Chemistry·29 Oct 201743. A laser pulse with wavelength 532 nm contains 3.85 m) of energy. How many photons are in the laser pulse?
OC userin Physics·28 Oct 201725.45 A 25.0-2 bulb is connected across the terminals of a 12.0-V battery having 3.50 2 of internal resistance. What per- centage of the power of the battery is dissipated across the internal resistance and hence is not available to the bulb?
OC userin Accounting·30 Oct 2017PROBLEM 7-19 Second Stage Allocations and Product Margins [LO7-4, L07-5] Pixel Studio, Inc., is a small company that creates computer-generated animations for films and television. Much of the company's work consists of short commercials for television, but the com- pany also does realistic computer animations for special effects in movies The young founders of the company have become increasingly concerned with the eco- nomics of the business particularly since many competitors have sprung up recently in the local area. To help understand the company's cost structure, an activity-based costing system has been designed. Three major activities are carried out in the company: animation concept, animation production, and contract administration. The animation concept activity is carried out at the contract proposal stage when the company bids on projects. This is an intensive activity that involves individuals from all parts of the company in creating story boards and prototype stills to be shown to the prospective client. Once a project is accepted by the client, the anima- tion goes into production and contract administration begins. Almost all of the work involved in animation production is done by the technical staff, whereas the administrative staff is largely responsible for contract administration. The activity cost pools and their activity measures are listed below: Activity Cost Pool Activity Measure Activity Rate Animation concept ............. Animation production Contract administration .......... Number of proposals Minutes of completed animation Number of contracts $6,040 per proposal $7,725 per minute $6,800 per contract These activity rates include all of the company's costs, except for the costs of idle capacity and organization-sustaining costs. There are no direct labor or direct materials costs. Preliminary analysis using these activity rates has indicated that the local commercial seg- ment of the market may be unprofitable. This segment is highly competitive. Producers of local commercials may ask three or four companies like Pixel Studio to bid, which results in an unusu- ally low ratio of accepted contracts to bids. Furthermore, the animation sequences tend to be much shorter for local commercials than for other work. Since animation work is billed at fairly standard rates according to the running time of the completed animation, this means that the revenues from these short projects tend to be below average. Data concerning activity in the local commercial market appear below: Local Commercials Activity Measure Number of proposals .... Minutes of completed animation ... Number of contracts .. Doa The total sales from the 10 contracts for local commercials was $180,000. Required: 1. Determine the cost of serving the local commercial market. 2. Prepare a report showing the margin earned serving the local commercial market. (Remem- ber, this company has no direct materials or direct labor costs.) 3. What would you recommend to management concerning the local commercial market?
OC userin Chemistry·29 Oct 20177. How and by whom was the electron discovered? What basic properties of the electron were reported with its discovery?