ÌâÄ¿ÄÚÈÝ

19£®Cr£¨VI£©¶ÔAÌå¾ßÓÐÖ°©¡¢ÖÂÍ»±ä×÷Óã®ÌúÑõÌå·¨£¨ÌúÑõÌåÊÇ×é³ÉÀàËÆÓÚFe3O4µÄ¸´ºÏÑõ»¯ÎÆäÖв¿·ÖFe£¨III£©¿É±»Cr£¨III£©µÈËù´ú»»£©ÊÇĿǰ´¦ÀíCr£¨VI£©·ÏË®µÄ³£¼û·½·¨Ö®Ò»£¬Æä¹¤ÒÕÁ÷³ÌÈçͼ£º

£¨1£©Cr£¨VI£©°üÀ¨CrO42-ºÍCr2O72-£¬ÎÒ¹úÅŷűê×¼ÊÇÿÉý·ÏË®¸õÔªËØº¬Á¿²»³¬¹ý0.5mg•L-1£®
¢Ùת»¯·´Ó¦£º2CrO42-+2H+?Cr2O72-+H2OµÄƽºâ³£Êý±í´ïʽΪK=$\frac{c£¨C{r}_{2}{{O}_{7}}^{2-}£©}{{c}^{2}£¨Cr{{O}_{4}}^{2-}£©•{c}^{2}£¨{H}^{+}£©}$£®
¢ÚȡijCr£¨VI£©·ÏË®£¨Ö»º¬CrO42-£©Óë2.0¡Á1 0-4mol•L-lAgNO3ÈÜÒºµÈÌå»ý»ìºÏ£¬ÓÐרºìÉ«Ag2CrO4³Áµí£¬ÔòÔ­·ÏË®ÖÐÁù¼Û¸õ³¬±ê20.8±¶ÒÔÉÏ[ÒÑÖªKsp£¨Ag2CrO4£©=1.0¡Á10-12]£®
£¨2£©ÌúÑõÌå·¨´¦Àíº¬Cr2O72-·ÏË®µÄ¹¤ÒÕÁ÷³ÌÖУº
¢Ù¡°·´Ó¦²Û¡±Öз¢Éú·´Ó¦µÄÀë×Ó·½³ÌʽΪCr2O72-+6Fe2++14H+=2Ce2++6Fe3++7H2O£®
¢ÚÔÚ¡°¼ÓÈÈÆØÆø²Û¡±ÖÐͨÈëѹËõ¿ÕÆøµÄÄ¿µÄÊǽ«²¿·ÖÇâÑõ»¯ÑÇÌúÑõ»¯ÎªÇâÑõ»¯ÌúÒÔÐγÉÌúÑõÌ壮
£¨3£©ÊµÑéÊÒÓÐ100Lº¬Cr£¨VI£©Ç¿ËáÐÔ·ÏË®£¨Ö»º¬Cr2O72-£©£¬¾­²â¶¨Cr2O72-Ũ¶ÈΪ2¡Á10-4mol/L£®Éè¼ÆÍ¨¹ýÏòÆäÖмÓÈëÒ»¶¨Á¿µÄFeSO4•7H2O£¬½Á°è³ä·Ö·´Ó¦ºóÔÙ¼ÓÈëNaOHÈÜÒºµ÷½ÚpH£¬½Á°è²¢¼ÓÈÈ£¬Ê¹CrºÍFeÇ¡ºÃ¾ùת»¯ÎªFe3+[Fe2+•Fe1-x3+Cry3+]O4£®£¨²»¿¼ÂÇ΢Á¿µÄ²ÐÁô£©£®
¼ÆËã100L¸Ã·ÏË®Ðè¼ÓÈëµÄFeSO4•7H2OµÄÖÊÁ¿£¬Ð´³ö¼ÆËã¹ý³Ì£®

·ÖÎö £¨1£©¢Ù¸ù¾Ý»¯Ñ§Æ½ºâ³£ÊýΪÉú³ÉÎïŨ¶ÈÃÝÖ®»ýÓë·´Ó¦ÎïŨ¶ÈÃÝÖ®»ýÖ®±ÈÁÐʽ£»
¢Ú¸ù¾ÝKsp£¨Ag2CrO4£©¼ÆËãCrO42-µÄŨ¶È¿ÉµÃ£»
£¨2£©¢Ù¡°·´Ó¦²Û¡±ÖÐÔÚÏ¡ÁòËáµÄ×÷ÓÃÏÂCr2O72-Ñõ»¯ÁòËáÑÇÌúÉú³ÉÈý¼Û¸õÀë×ÓºÍÌúÀë×Ó£»
¢ÚÔÚ¡°¼ÓÈÈÆØÆø²Û¡±¼ÓÈëÇâÑõ»¯Äƽ«ÈÜÒºÖеÄÌúÀë×Ó¡¢ÑÇÌúÀë×ÓÉú³ÉÇâÑõ»¯ÎͨÈëѹËõ¿ÕÆø½«²¿·ÖÇâÑõ»¯ÑÇÌúÑõ»¯ÎªÇâÑõ»¯ÌúÒÔÐγÉÌúÑõÌ壻
£¨3£©¸ù¾Ý·´Ó¦Cr2O72-+6Fe2++14H+=2Ce2++6Fe3++7H2O¼ÆËãÏûºÄµÄn£¨Fe2+£©Éú³ÉµÄn£¨Ce3+£©ºÍn£¨Fe3+£©£¬ÔÙ¼ÆËãÐγÉÌúÑõÌåÖеÄÑÇÌúÀë×ÓµÄÎïÖʵÄÁ¿£¬¸ù¾ÝÌúÔªËØÖÊÁ¿ÊØºã¼ÆËã¿ÉµÃ£®

½â´ð ½â£º£¨1£©¢Ù2CrO42-+2H+?Cr2O72-+H2OµÄƽºâ³£Êý±í´ïʽΪK=$\frac{c£¨C{r}_{2}{{O}_{7}}^{2-}£©}{{c}^{2}£¨Cr{{O}_{4}}^{2-}£©•{c}^{2}£¨{H}^{+}£©}$£»
¹Ê´ð°¸Îª£º$\frac{c£¨C{r}_{2}{{O}_{7}}^{2-}£©}{{c}^{2}£¨Cr{{O}_{4}}^{2-}£©•{c}^{2}£¨{H}^{+}£©}$£»
¢ÚijCr£¨VI£©·ÏË®£¨Ö»º¬CrO42-£©Óë2.0¡Á1 0-4mol•L-lAgNO3ÈÜÒºµÈÌå»ý»ìºÏ£¬Ôò»ìºÏÈÜÒºÖÐc£¨Ag+£©=1.0¡Á1 0-4mol•L-l£¬ÒÑÖªÖªKsp£¨Ag2CrO4£©=1.0¡Á10-12£¬»ìºÏÈÜÒºÖÐc£¨CrO42-£©=$\frac{Ksp£¨A{g}_{2}Cr{O}_{4}£©}{{c}^{2}£¨A{g}^{+}£©}$=$\frac{1.0¡Á1{0}^{-12}}{£¨1.0¡Á1{0}^{-4}£©^{2}}$=1.0¡Á1 0-4mol•L-l£¬¹ÊÔ­·ÏË®ÖÐc£¨CrO42-£©=2.0¡Á1 0-4mol•L-l=2.0¡Á1 0-4¡Á52¡Á103mg•L-1=10.4mg•L-1£¬Ô­·ÏË®ÖÐÁù¼Û¸õ³¬±ê10.4mg•L-1¡Â0.5mg•L-1=20.8±¶£»
¹Ê´ð°¸Îª£º20.8£»
£¨2£©¢Ù¡°·´Ó¦²Û¡±ÖÐÔÚÏ¡ÁòËáµÄ×÷ÓÃÏÂCr2O72-Ñõ»¯ÁòËáÑÇÌúÉú³ÉÈý¼Û¸õÀë×ÓºÍÌúÀë×Ó£¬·´Ó¦ÎïΪ£ºCr2O72-+6Fe2++14H+=2Ce2++6Fe3++7H2O£»
¹Ê´ð°¸Îª£ºCr2O72-+6Fe2++14H+=2Ce2++6Fe3++7H2O£»
¢ÚÔÚ¡°¼ÓÈÈÆØÆø²Û¡±¼ÓÈëÇâÑõ»¯Äƽ«ÈÜÒºÖеÄÌúÀë×Ó¡¢ÑÇÌúÀë×ÓÉú³ÉÇâÑõ»¯ÎͨÈëѹËõ¿ÕÆø½«²¿·ÖÇâÑõ»¯ÑÇÌúÑõ»¯ÎªÇâÑõ»¯ÌúÒÔÐγÉÌúÑõÌ壻
¹Ê´ð°¸Îª£º½«²¿·ÖÇâÑõ»¯ÑÇÌúÑõ»¯ÎªÇâÑõ»¯ÌúÒÔÐγÉÌúÑõÌ壻
£¨3£©ÓÐ100Lº¬Cr£¨VI£©Ç¿ËáÐÔ·ÏË®£¨Ö»º¬Cr2O72-£©£¬Cr2O72-Ũ¶ÈΪ2¡Á10-4mol/L£¬Ôòn£¨Cr2O72-£©=2¡Á10-4mol/L¡Á100L=0.0200mol£¬·´Ó¦Cr2O72-+6Fe2++14H+=2Ce2++6Fe3++7H2O£¬»¹Ô­·´Ó¦ÐèÏûºÄn1£¨Fe2+£©=0.1200mol£¬Í¬Ê±·´Ó¦Éú³ÉµÄn£¨Ce3+£©=0.0400mol£¬n£¨Fe3+£©=0.1200mol£¬
ÓëCe3+ºÍFe3+ÐγÉÌúÑõÌåµÄn2£¨Fe2+£©=$\frac{1}{2}$¡Án£¨Ce3+£©+$\frac{1}{2}$¡Án£¨Fe3+£©=0.0800mol£¬
n£¨FeSO4•7H2O£©=n1£¨Fe2+£©+n2£¨Fe2+£©=0.2000mol£¬
¹Ê¼ÓÈëµÄm£¨FeSO4•7H2O£©=0.2000mol¡Á278g/mol=55.6g£¬
´ð£º100L¸Ã·ÏË®Ðè¼ÓÈëµÄFeSO4•7H2OµÄÖÊÁ¿Îª55.6g£®

µãÆÀ ±¾Ì⿼²éÁËÎïÖÊÖÆ±¸·½°¸Éè¼Æ£¬Ö÷Òª¿¼²éÁË»¯Ñ§·½³ÌʽµÄÊéд¡¢ÊµÑé·½°¸ÆÀ¼Û¡¢Ñõ»¯»¹Ô­·´Ó¦µÈ£¬ÌâÄ¿ÄѶÈÖеȣ¬¼ÓÇ¿ËæÊý¾ÝµÄ´¦ÀíºÍ·ÖÎöÄÜÁ¦£¬²àÖØÓÚ¿¼²éѧÉúµÄ·ÖÎöÎÊÌâºÍ½â¾öÎÊÌâµÄÄÜÁ¿£¬×¢ÒâÏà¹Ø»ù´¡ÖªÊ¶µÄѧϰÓë»ýÀÛ£®

Á·Ï°²áϵÁдð°¸
Ïà¹ØÌâÄ¿

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

¾«Ó¢¼Ò½ÌÍø