ÄÚÈÝ·¢²¼¸üÐÂʱ¼ä : 2025/7/30 12:11:52ÐÇÆÚÒ» ÏÂÃæÊÇÎÄÕµÄÈ«²¿ÄÚÈÝÇëÈÏÕæÔĶÁ¡£
¶ÔpH×÷ͼ¼´¿ÉÇóµÃpKa
Èý¡¢¼ÆËãÌ⣨ÿÌâ8·Ö£¬¹²32·Ö£© 1£®¶þÔªÈõËáH2B£¬ÒÑÖªpH£½1.92ʱ£¬¦Ä¼ÆË㣺
£¨1£©H2BµÄKa1 ºÍKa2¡£
£¨2£©Èç¹ûÒÔ0.100 mol/LµÄNaOHÈÜÒºµÎ¶¨0.100 mol/LµÄH2B£¬µÎ¶¨ÖÁµÚÒ»
ºÍµÚ¶þ»¯Ñ§¼ÆÁ¿µãʱ£¬ÈÜÒºµÄpHÖµ¸÷Ϊ¶àÉÙ£¿¸÷Ñ¡ÓúÎÖÖָʾ¼Á£¿ ´ð£¨1£© ¦Ä¦Ä
-HB
H2B
H2B
£½¦Ä
HB-
£»pH£½6.22ʱ¦Ä
HB-
£½¦Ä
B2-
¡£
=¦Ä
-HBʱ£¬Ka1£½[H+] = 10 -1.92 = 1.20 ?10 -2
=¦Ä
2-Bʱ£¬ Ka2£½[H+] =10 -6.22 £½6.02?10 ¨C7
£¨2£©µÎ¶¨ÖÁµÚÒ»»¯Ñ§¼ÆÁ¿µãʱ£¬²úÎïΪHB-£¬cHB- =0.0500 mol/L, pH¡Ö4.07, Ñ¡ÓÃMOΪָʾ¼Á¡£
µÎ¶¨ÖÁµÚ¶þ»¯Ñ§¼ÆÁ¿µãʱ£¬²úÎïΪB2-£¬cB2- =0.0333 mol/L£¬[OH-] =
Kb1CB2?= 2.35 ?10 ¨C5 mol/L£¬pOH = 4.63, pH = 9.37, Ñ¡PP Ϊָʾ
¼Á¡£
2. 25.00mL KIÈÜÒº£¬ÓÃ10.00mL 0.0500mol/L KIO3ÈÜÒº´¦Àíºó£¬Öó·ÐÈÜÒº³ýÈ¥I2¡£ÀäÈ´ºó¼ÓÈë¹ýÁ¿KIÈÜҺʹ֮ÓëÊ£ÓàKIO3·´Ó¦£¬È»ºó½«ÈÜÒºµ÷ÕûÖÁÖÐÐÔ¡£Îö³öµÄI2ÓÃ0.1008mol/L Na2S2O3ÈÜÒºµÎ¶¨£¬ÏûºÄ21.14mL,ÇóÔKIÈÜÒºµÄŨ¶È£¨10·Ö£©¡£ ´ð£ºnKI= (cIO3-VIO3-£1/6cS2O32-VS2O32-)¡Á5£½0.7242 mmol cKI= 0.7242/25.00=0.02897 mol/L
3.ij¿óʯº¬ÍÔ¼0.12£¥£¬ÓÃË«»·¼ºÍª²Ýõ£¶þëêÏÔÉ«¹â¶È·¨²â¶¨¡£ÊÔÑùÈܽâºóתÈë100mlÈÝÁ¿Æ¿ÖУ¬ÔÚÊÊÒËÌõ¼þÏÂÏÔÉ«£¬¶¨ÈÝ¡£ÓÃ1cm±ÈÉ«Ãó£¬ÔÚ²¨³¤600nm²â¶¨Îü¹â¶È£¬ÒªÇó²âÁ¿Îó²î×îС£¬Ó¦¸Ã³ÆÈ¡ÊÔÑù¶àÉÙ¿Ë£¿¦Å£½1.68¡Á104£¨Lmol-1cm-1£©£¬ACu=63.5£©
91
´ð£º¸ù¾Ý¹â¶È²âÁ¿Îó²î¹«Ê½¿ÉÖª£ºµ±Îü¹â¶ÈA£½0.434ʱ£¬Îó²î×îС£¬
ÒÑÖªb=1, ¦Å£½1.68¡Á104£¬¸ù¾ÝA=¦Åbc c = A/¦Åb£½0.434/£¨1.68¡Á104¡Á1£© £½2.58¡Á10-5 (mol/L) 100mlÓÐÉ«ÈÜÒºÖÐCuµÄº¬Á¿Îª
m=cVM £½ 2.58¡Á10-5¡Á100¡Á10-3¡Á63.5 £½1.64¡Á10-4
(g)
ÒÑ֪ij¿óº¬ÍÔ¼0.12£¥£¬ÔòÓ¦³ÆÈ¡ÊÔÑùÖÊÁ¿Îª£º (1.64¡Á10-4/ms)¡Á100=0.12 ms=0.14g
4£®ÓÃÓлúÈܼÁ´Ó100mLË®ÈÜÒºÖÐÝÍȡijҩÎï³É·ÖAÁ½´Î£¬Ã¿´ÎÓÃÓлúÈܼÁ10mL£¬Óûʹ×ÜÝÍÈ¡ÂÊ´ï99%ÒÔÉÏ, ÔòAÔÚÁ½ÏàÖеķÖÅä±ÈDӦΪ¶à´ó? ÝÍÈ¡Íêºó½«ÓлúÏàºÏ²¢£¬ÓõÈÌå»ýˮϴµÓÒ»´Î, Ôò½«Ëðʧ¶à´ó±ÈÀý?£¨²»¿¼ÂÇÈÜÒºÖÐµÄÆäËüÒòËØÓ°Ï죩 ´ð£º ÓÉÌâÒâ¿ÉÖª£º
1-99%=[Vw/(DVo+Vw)]2
µÃD=90
Ëðʧ£¥£½1/(90+1)¡Á100£¥=1.1%
92