ÌâÄ¿ÄÚÈÝ

10£®»¯Ñ§¹¤ÒµÖлá²úÉú´óÁ¿º¬¸õ·ÏË®£¬Ö±½ÓÅÅ·Å»á²úÉúÎÛȾ£®
£¨1£©¹¤ÒµÉÏ´¦ÀíËáÐÔº¬Cr2O72-·ÏË®µÄ·½·¨ÈçÏ£º
¢ÙSO2»¹Ô­·¨£ºÏò1000Lº¬0.002mol•L-1 Cr2O72-µÄËáÐÔ·ÏË®ÖÐͨÈëSO2ʹCr2O72-È«²¿×ª»¯ÎªCr3+£¬ÖÁÉÙÐèҪͨÈë134.4L SO2£¨±ê×¼×´¿ö£©
¢ÚÌúм»¹Ô­·¨£ºÏòº¬Cr2O72-µÄËáÐÔ·ÏË®ÖмÓÈë·ÏÌúм£¬¼ÓÈȳä·Ö·´Ó¦ºó£¬¼ÓÈëÊìʯ»Òµ÷½ÚÈÜÒºµÄpH£¬Ê¹Cr3+ÍêÈ«³Áµí£®
ÒÑÖª25¡æÊ±£¬Ksp[Cr£¨OH£©3]=6.3¡Á10-31£®ÓûʹÈÜÒºÖвÐÓàCr3+µÄÎïÖʵÄÁ¿Å¨¶ÈΪ6.3¡Á10-7 mol•L-1£¬Ó¦µ÷½ÚÈÜÒºµÄpH=6£®
£¨2£©¸õÔªËØ×ÜŨ¶ÈµÄ²â¶¨£º×¼È·ÒÆÈ¡20.00mLº¬Cr2O72-ºÍCr3+µÄËáÐÔ·ÏË®£¬ÏòÆäÖмÓÈë×ãÁ¿£¨NH4£©2S2O8ÈÜÒº½«Cr3+Ñõ»¯³ÉCr2O72-£¬Öó·Ð³ýÈ¥¹ýÁ¿£¨NH4£©2S2O8£»ÏòÉÏÊöÈÜÒºÖмÓÈë¹ýÁ¿µÄKIÈÜÒº£¬³ä·Ö·´Ó¦ºó£¬ÒÔµí·ÛΪָʾ¼Á£¬ÏòÆäÖеμÓ0.03mol•L-1µÄNa2S2O3±ê×¼ÈÜÒº£¬ÖÕµãʱÏûºÄNa2S2O3ÈÜÒº20.00mL£®
¢ÙÉÏÊö²Ù×÷¹ý³ÌÖУ¬ÈôÎÞÖó·Ð²Ù×÷£¬Ôò²â¶¨µÄ¸õÔªËØ×ÜŨ¶È»áÆ«¸ß£®
¢Ú¼ÆËã·ÏË®ÖиõÔªËØ×ÜŨ¶È£¨µ¥Î»£ºmg•L-1£¬Ð´³ö¼ÆËã¹ý³Ì£©Cr2O72-¡«3I2¡«6S2O32-£¬¸ù¾Ý·½³Ìʽȷ¶¨¹ØÏµCr2O72-¡«3I2¡«6S2O32-
n£¨Cr2O72-£©=$\frac{n£¨{S}_{2}{O}_{3}^{2-}£©}{6}$=$\frac{0.03¡Á20.00¡Á1{0}^{-3}}{6}$mol£¬ËùÒÔc£¨Cr2O72-£©=$\frac{\frac{0.03¡Á20¡Á1{0}^{-3}}{6}}{20¡Á1{0}^{-3}}$=0.005mol/L
ËùÒÔ·ÏË®ÖиõÔªËØ×ÜŨ¶È=0.005¡Á2¡Á52¡Á1000=520 mg•L-1£®
ÒÑÖª²â¶¨¹ý³ÌÖз¢ÉúµÄ·´Ó¦ÈçÏ£º
¢Ù2Cr3++3S2O82-+7H2O=Cr2O72-+6SO42-+14H+
¢ÚCr2O72-+6I-+14H+=2Cr3++3I2+7H2O
¢ÛI2+2S2O32-=2I-+S4O62-£®

·ÖÎö £¨1£©¢ÙSO2ʹCr2O72-È«²¿×ª»¯ÎªCr3+£¬ËùÒÔ3SO2¡«¡«Cr2O72-£¬¸ù¾Ý¹ØÏµÊ½Çó¶þÑõ»¯ÁòµÄÌå»ý£»
¢ÚKsp[Cr£¨OH£©3]=c£¨Cr3+£©•c3£¨OH-£©=6.3¡Á10-31£¬ÓûʹÈÜÒºÖвÐÓàCr3+µÄÎïÖʵÄÁ¿Å¨¶ÈΪ6.3¡Á10-7 mol•L-1£¬ËùÒÔc£¨OH-£©=$\root{3}{\frac{6.3¡Á1{0}^{-31}}{6.3¡Á1{0}^{-7}}}$=10-8mol/L£¬Ó¦µ÷½ÚÈÜÒºµÄpOH=8£¬ÔòpH=6£»
£¨2£©¢ÙÈôÎÞÖó·Ð²Ù×÷£¬Ôò¹ýÁ¿£¨NH4£©2S2O8ÏûºÄCr2O72-£¬ËùÒÔÔò²â¶¨µÄ¸õÔªËØ×ÜŨ¶È»áÆ«¸ß£»
¢ÚÓÉ¢Ù2Cr3++3S2O82-+7H2O=Cr2O72-+6SO42-+14H+
¢ÚCr2O72-+6I-+14H+=2Cr3++3I2+7H2O
¢ÛI2+2S2O32-=2I-+S4O62-µÃ£ºCr2O72-¡«3I2¡«6S2O32-£¬ÓÉ´Ë·ÖÎö½â´ð£®

½â´ð ½â£º£¨1£©¢ÙSO2ʹCr2O72-È«²¿×ª»¯ÎªCr3+£¬
ËùÒÔ3SO2¡«¡«Cr2O72-£¬
   3¡Á22.4L      1mol
     V        1000L¡Á0.002mol•L-1 
ËùÒÔV=$\frac{1000L¡Á0.002mol•{L}^{-1}¡Á3¡Á22.4L}{1mol}$=134.4L£¬¹Ê´ð°¸Îª£º134.4£»      
¢ÚKsp[Cr£¨OH£©3]=c£¨Cr3+£©•c3£¨OH-£©=6.3¡Á10-31£¬ÓûʹÈÜÒºÖвÐÓàCr3+µÄÎïÖʵÄÁ¿Å¨¶ÈΪ6.3¡Á10-7 mol•L-1£¬ËùÒÔc£¨OH-£©=$\root{3}{\frac{6.3¡Á1{0}^{-31}}{6.3¡Á1{0}^{-7}}}$=10-8mol/L£¬Ó¦µ÷½ÚÈÜÒºµÄpOH=8£¬ÔòpH=6£¬¹Ê´ð°¸Îª£º6£»
£¨2£©¢ÙÈôÎÞÖó·Ð²Ù×÷£¬Ôò¹ýÁ¿£¨NH4£©2S2O8ÏûºÄCr2O72-£¬ËùÒÔÔò²â¶¨µÄ¸õÔªËØ×ÜŨ¶È»áÆ«¸ß£¬¹Ê´ð°¸Îª£ºÆ«¸ß£»
¢ÚÓÉ¢Ù2Cr3++3S2O82-+7H2O=Cr2O72-+6SO42-+14H+
¢ÚCr2O72-+6I-+14H+=2Cr3++3I2+7H2O
¢ÛI2+2S2O32-=2I-+S4O62-µÃ£ºCr2O72-¡«3I2¡«6S2O32-£¬¸ù¾Ý·½³Ìʽȷ¶¨¹ØÏµCr2O72-¡«3I2¡«6S2O32-
n£¨Cr2O72-£©=$\frac{n£¨{S}_{2}{O}_{3}^{2-}£©}{6}$=$\frac{0.03¡Á20.00¡Á1{0}^{-3}}{6}$mol£¬ËùÒÔc£¨Cr2O72-£©=$\frac{\frac{0.03¡Á20¡Á1{0}^{-3}}{6}}{20¡Á1{0}^{-3}}$=0.005mol/L
ËùÒÔ·ÏË®ÖиõÔªËØ×ÜŨ¶È=0.005¡Á2¡Á52¡Á1000=520 mg•L-1£¬´ð£ºCr2O72-¡«3I2¡«6S2O32-£¬¸ù¾Ý·½³Ìʽȷ¶¨¹ØÏµCr2O72-¡«3I2¡«6S2O32-
n£¨Cr2O72-£©=$\frac{n£¨{S}_{2}{O}_{3}^{2-}£©}{6}$=$\frac{0.03¡Á20.00¡Á1{0}^{-3}}{6}$mol£¬ËùÒÔc£¨Cr2O72-£©=$\frac{\frac{0.03¡Á20¡Á1{0}^{-3}}{6}}{20¡Á1{0}^{-3}}$=0.005mol/L
ËùÒÔ·ÏË®ÖиõÔªËØ×ÜŨ¶È=0.005¡Á2¡Á52¡Á1000=520 mg•L-1£®

µãÆÀ ±¾Ì⿼²éÑõ»¯»¹Ô­·´Ó¦µÄµÎ¶¨Ô­Àí£¬Ñ§ÉúҪѧ»á¸ù¾Ý·´Ó¦·½³ÌʽÁÐʽ¼ÆËãºÍÈܶȻýµÄÏà¹ØÖªÊ¶£¬ÓÐÒ»¶¨µÄÄѶȣ®

Á·Ï°²áϵÁдð°¸
Ïà¹ØÌâÄ¿

Î¥·¨ºÍ²»Á¼ÐÅÏ¢¾Ù±¨µç»°£º027-86699610 ¾Ù±¨ÓÊÏ䣺58377363@163.com

¾«Ó¢¼Ò½ÌÍø