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几种重要的金属复习第一部分：镁和铝一、镁和铝的性质1．镁单质物理性质和化学性质镁元素位于元素周期表中的第周期族，最外层电子数是，容易电子，所以镁是一种比较。

写出下列反应的化学方程式（离子反应写离子方程式）：镁条在氧气中燃烧镁与醋酸反应镁与水反应镁与CO2反应2．铝单质的物理性质和化学性质铝有优良的导电性和密度小，铝元素位于元素周期表中第周期族，化学性质较活泼，在溶液中以和存在。

写出下列反应的化学方程式（离子反应写离子方程式）铝在氧气中燃烧，放出大量的热和耀眼的白光铝与盐酸应铝溶于NaOH溶液铝与沸水反应用镁条引燃铝粉和氧化铁的混合物这一反应也被称作反应，类似的还有铝和二氧化锰的反应思考：镁在空气中燃烧产物及质量变化？例：1.将相同质量的镁条分别放在①氧气中，②氮气中，③空气中，④二氧化碳中燃烧。

燃烧后所得固体产物的质量按由小到大的顺序排列是2. 将等物质的量的镁和铝相混合，取等质量该混合物四份，分别加到足量的下列溶液中，充分反应后，放出氢气最多的是A．3mol·L－1HCl B．4mol·L－1HNO3C．8mol·L－1NaOH D．18mol·L－1H2SO4二、铝的重要化合物1．氧化铝氧化铝属于化合物，室温下是一种白色固体，熔点很高，可作耐火材料。

氧化铝属于典型的氧化物，与都能反应，写出下列反应的化学方程式（离子反应写离子方程式）氧化铝溶于盐酸电解熔融的氧化铝氧化铝与烧碱反应氢氧化铝它是一种难溶于水的色状物质，具有较强的吸附能力。

它是一种典型的氢氧化物。

写出下列反应的化学方程式（离子反应写离子方程式）Al(OH)3与盐酸反应Al(OH)3与NaOH反应Al(OH)3的实验室制取思考：（1）为什么Mg的化学性质比Al活泼？实验事实有？（2）等质量铝分别跟足量盐酸，NaOH溶液反应产生的H2等吗？耗酸、碱量怎样？三、知识点分析1．铝三角，离子方程式的书写向AlCl 3溶液中滴加NaOH 溶液至过量 向NaOH 溶液中滴加AlCl 3溶液至过量向NaAlO 2溶液中滴加盐酸至过量 向盐酸中滴加NaAlO 2溶液至过量例：a ml 0.5mol/L AlCl 3溶液与b ml c mol/LNaOH 溶液混合后，得到3.9g 沉淀，则下列说法正确的是 A. 若a 、b 均为1000时，c 的值只有一个。

TL H 7340LM79XX Series 3-Terminal Negative RegulatorsNovember1994LM79XX Series3-Terminal Negative RegulatorsGeneral DescriptionThe LM79XX series of3-terminal regulators is available withfixed output voltages of b5V b8V b12V and b15VThese devices need only one external component a com-pensation capacitor at the output The LM79XX series ispackaged in the TO-220power package and is capable ofsupplying1 5A of output currentThese regulators employ internal current limiting safe areaprotection and thermal shutdown for protection against vir-tually all overload conditionsLow ground pin current of the LM79XX series allows outputvoltage to be easily boosted above the preset value with aresistor divider The low quiescent current drain ofthese devices with a specified maximum change with lineand load ensures good regulation in the voltage boostedmodeFor applications requiring other voltages see LM137datasheetFeaturesY Thermal short circuit and safe area protectionY High ripple rejectionY1 5A output currentY4%tolerance on preset output voltage Connection DiagramsTO-220PackageTL H 7340–14Front ViewOrder Number LM7905CT LM7912CT or LM7915CTSee NS Package Number TO3BTypical ApplicationsFixed RegulatorTL H 7340–3Required if regulator is separated from filter capacitor bymore than3 For value given capacitor must be solidtantalum 25m F aluminum electrolytic may be substitutedRequired for stability For value given capacitor must besolid tantalum 25m F aluminum electrolytic may be substi-tuted Values given may be increased without limitFor output capacitance in excess of100m F a high currentdiode from input to output(1N4001 etc )will protect theregulator from momentary input shortsC1995National Semiconductor Corporation RRD-B30M115 Printed in U S AAbsolute Maximum Ratings (Note 1)If Military Aerospace specified devices are required please contact the National Semiconductor Sales Office Distributors for availability and specifications Input Voltage (V o e b 5V)b 25V (V o e b 12V and b 15V)b 35VInput-Output Differential (V o e b 5V)25V (V o e b 12V and b 15V)30VPower Dissipation (Note 2)Internally LimitedOperating Junction Temperature Range 0 C to a 125 CStorage Temperature Rangeb 65 C to a 150 C Lead Temperature (Soldering 10sec )230 CElectrical Characteristics Conditions unless otherwise noted I OUT e 500mA C IN e 2 2m F C OUT e 1m F0 C s T J s a 125 C Power Dissipation s 1 5WPart Number LM7905CUnitsOutput Voltageb 5V Input Voltage (unless otherwise specified)b 10VSymbol Parameter ConditionsMinTypMaxV OOutput VoltageT J e 25 Cb 4 8b 5 0b 5 2V 5mA s I OUT s 1A b 4 75b 5 25V P s 15W(b 20s V IN s b 7)V D V OLine RegulationT J e 25 C (Note 3)850mV (b 25s V IN s b 7)V 215mV (b 12s V IN s b 8)V D V OLoad RegulationT J e 25 C (Note 3)5mA s I OUT s 1 5A15100mV 250mA s I OUT s 750mA 550mV I Q Quiescent Current T J e 25 C 12mA D I QQuiescent Current With Line0 5mA Change(b 25s V IN s b 7)V With Load 5mA s I OUT s 1A0 5mA V n Output Noise Voltage T A e 25 C 10Hz s f s 100Hz 125m V Ripple Rejection f e 120Hz5466dB (b 18s V IN s b 8)V Dropout VoltageT J e 25 C I OUT e 1A 1 1V I OMAXPeak Output Current T J e 25 C 2 2A Average Temperature I OUT e 5mA 0 4mV CCoefficient of 0C s T J s 100 COutput VoltageTypical Applications (Continued)Variable OutputTL H 7340–2Improves transient response and ripple rejection Do not increase beyond 50m F V OUT e V SETR1a R2R2JSelect R2as followsLM7905CT 300X LM7912CT 750X LM7915CT1k2Electrical Characteristics (Continued)Conditions unless otherwise noted I OUT e 500mA C IN e 2 2m F C OUT e 1m F 0 C s T J s a 125 C Power Dissipation e 1 5WPart Number LM7912CLM7915CUnitsOutput Voltageb 12V b 15V Input Voltage (unless otherwise specified)b 19Vb 23VSymbol Parameter ConditionsMinTyp Max Min TypMaxV OOutput VoltageT J e 25 Cb 11 5b 12 0b 12 5b 14 4b 15 0b 15 6V 5mA s I OUT s 1A b 11 4b 12 6b 14 25b 15 75V P s 15W(b 27s V IN s b 14 5)(b 30s V IN s b 17 5)V D V OLine RegulationT J e 25 C (Note 3)5805100mV (b 30s V IN s b 14 5)(b 30s V IN s b 17 5)V 330350mV (b 22s V IN s b 16)(b 26s V IN s b 20)V D V OLoad RegulationT J e 25 C (Note 3)5mA s I OUT s 1 5A1520015200mV 250mA s I OUT s 750mA 575575mV I Q Quiescent Current T J e 25 C 1 531 53mA D I QQuiescent Current With Line0 50 5mA Change(b 30s V IN s b 14 5)(b 30s V IN s b 17 5)V With Load 5mA s I OUT s 1A0 50 5mA V n Output Noise Voltage T A e 25 C 10Hz s f s 100Hz 300375m V Ripple Rejection f e 120Hz54705470dB (b 25s V IN s b 15)(b 30s V IN s b 17 5)V Dropout VoltageT J e 25 C I OUT e 1A 1 11 1V I OMAXPeak Output Current T J e 25 C 2 22 2A Average Temperature I OUT e 5mA b 0 8b 1 0mV CCoefficient of 0C s T J s 100 COutput VoltageNote 1 Absolute Maximum Ratings indicate limits beyond which damage to the device may occur Operating Ratings indicate conditions for which the device is intended to be functional but do not guarantee Specific Performance limits For guaranteed specifications and test conditions see the Electrical Characteristics Note 2 Refer to Typical Performance Characteristics and Design Considerations for detailsNote 3 Regulation is measured at a constant junction temperature by pulse testing with a low duty cycle Changes in output voltage due to heating effects must be taken into accountTypical Applications (Continued)Dual Trimmed SupplyTL H 7340–43Design ConsiderationsThe LM79XX fixed voltage regulator series has thermaloverload protection from excessive power dissipation inter-nal short circuit protection which limits the circuit’s maxi-mum current and output transistor safe-area compensationfor reducing the output current as the voltage across thepass transistor is increasedAlthough the internal power dissipation is limited the junc-tion temperature must be kept below the maximum speci-fied temperature(125 C)in order to meet data sheet specifi-cations To calculate the maximum junction temperature orheat sink required the following thermal resistance valuesshould be usedTyp Max Typ Max Package i JC i JC i JA i JAC W C W C W C WTO-2203 05 06040P D MAX e T J Max b T Ai JC a i CAorT J Max T Ai JAi CA e i CS a i SA(without heat sink) Solving for T JT J e T A a P D(i JC a i CA)ore T A a P D i JA(without heat sink)WhereT J e Junction TemperatureT A e Ambient TemperatureP D e Power Dissipationi JA e Junction-to-Ambient Thermal Resistancei JC e Junction-to-Case Thermal Resistancei CA e Case-to-Ambient Thermal Resistancei CS e Case-to-Heat Sink Thermal Resistancei SA e Heat Sink-to-Ambient Thermal ResistanceTypical Applications(Continued)Bypass capacitors are necessary for stable operation of theLM79XX series of regulators over the input voltage and out-put current ranges Output bypass capacitors will improvethe transient response by the regulatorThe bypass capacitors (2 2m F on the input 1 0m F on theoutput)should be ceramic or solid tantalum which havegood high frequency characteristics If aluminum electrolyt-ics are used their values should be10m F or larger Thebypass capacitors should be mounted with the shortestleads and if possible directly across the regulator termi-nalsHigh Stability1Amp RegulatorTL H 7340–5Load and line regulation k0 01%temperature stability s0 2%Determine Zener currentSolid tantalumSelect resistors to set output voltage 2ppm C tracking suggested4Typical Applications (Continued)Current SourceI OUT e 1mA a5V R1TL H 7340–7Light Controller Using Silicon Photo CellTL H 7340–8Lamp brightness increase until i I e i Q ( 1mA)a 5V R1Necessary only if raw supply filter capacitor is more than 2 from LM7905CT5Typical Applications(Continued)High-Sensitivity Light ControllerTL H 7340–9Lamp brightness increases until i i e5V R1(I i can be set as low as1m A)Necessary only if raw supply filter capacitor is more than2 from LM7905g15V 1Amp Tracking RegulatorsTL H 7340–1(b15)(a15)Load Regulation at D I L e1A40mV2mVOutput Ripple C IN e3000m F I L e1A100m Vrms100m VrmsTemperature Stability50mV50mVOutput Noise10Hz s f s10kHz150m Vrms150m VrmsResistor tolerance of R4and R5determine matching of(a)and(b)outputsNecessary only if raw supply filter capacitors are more than3 from regu-lators6Schematic Diagramsb 5VT L H 7340–127Schematic Diagrams (Continued)b 12V a n d b 15VT L H 7340–1389L M 79X X S e r i e s 3-T e r m i n a l N e g a t i v e R e g u l a t o r sPhysical Dimensions inches (millimeters)TO-220Outline Package (T)Order Number LM7905CT LM7912CT or LM7915CTNS Package Number T03BLIFE SUPPORT POLICYNATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL SEMICONDUCTOR CORPORATION As used herein 1 Life support devices or systems are devices or 2 A critical component is any component of a life systems which (a)are intended for surgical implant support device or system whose failure to perform can into the body or (b)support or sustain life and whose be reasonably expected to cause the failure of the life failure to perform when properly used in accordance support device or system or to affect its safety or with instructions for use provided in the labeling can effectivenessbe reasonably expected to result in a significant injury to the userNational Semiconductor National Semiconductor National Semiconductor National Semiconductor CorporationEuropeHong Kong LtdJapan Ltd1111West Bardin RoadFax (a 49)0-180-530858613th Floor Straight Block Tel 81-043-299-2309。