Question

16£®£¨1£©MgCl₂µÄË®ÈÜÒº³ÊËᣨÌî¡°Ëᡱ¡¢¡°ÖС±¡¢¡°¼î¡±£©ÐÔ£¬Ô­ÒòÊÇ£¨ÓÃÀë×Ó·½³Ìʽ±íʾ£©£ºMg²⁺+2H₂O?Mg£¨OH£©₂+2H⁺
£¨2£©ÎªÁ˳ýÈ¥MgCl₂ËáÐÔÈÜÒºÖеÄFe³⁺£¬¿ÉÔÚ¼ÓÈȽÁ°èµÄÌõ¼þϼÓÈëÒ»ÖÖÊÔ¼Á£¬¹ýÂ˺ó£¬ÔÙÏòÂËÒºÖмÓÈëÊÊÁ¿µÄÑÎËᣬÕâÖÖÊÔ¼ÁÊÇB
A£®NaOHB£®MgO      C£®Na₂CO₃     D£®NH₃•H₂O
£¨3£©ÔÚ25¡æÏ£¬½«a mol•L^-1µÄ°±Ë®Óë0.01mol•L^-1µÄÑÎËáµÈÌå»ý»ìºÏ£¬²âµÃ·´Ó¦ºóµÄÈÜÒºÖÐc£¨NH₄⁺£©=c£¨Cl^-£©£¬ÔòÈÜÒº³ÊÖРÐÔ£¨Ìî¡°Ëᡱ¡¢¡°¼î¡±»ò¡°ÖС±£©£®
£¨4£©ÈôÒÔAµã±íʾ25¡æʱˮÔÚµçÀëƽºâʱµÄÀë×ÓŨ¶È£¬µ±Î¶ÈÉý¸ßµ½100¡æʱ£¬Ë®µÄµçÀëƽºâ״̬´ïµ½Bµã£¬Ôò´ËʱˮµÄÀë×Ó»ýÊÇ10^-12£®½«pH=8µÄBa£¨OH£©₂ÈÜÒºÓëpH=5µÄÏ¡ÑÎËá»ìºÏ£¬±£³Ö100¡æµÄºãΣ¬Óûʹ»ìºÏÈÜÒºpH=7£¬ÔòBa£¨OH£©₂ÓëÑÎËáµÄÌå»ýÖ®±ÈΪ10£º1£® 

£¨5£©25¡æʱ£¬ÏòŨ¶È¾ùΪ0.1mol•L^-1µÄMgCl₂ºÍCuCl₂»ìºÏÈÜÒºÖÐÖðµÎ¼ÓÈ백ˮ£¬ÏÈÉú³ÉCu£¨OH£©₂³Áµí£¨Ìѧʽ£©£¬Éú³É¸Ã³ÁµíµÄÀë×Ó·½³ÌʽΪCu²⁺+2NH₃•H₂O=Cu£¨OH£©₂¡ý+2NH₄⁺£®£¨ÒÑÖª25¡æʱK_sp[Mg£¨OH£©₂]=1.8¡Á10^-11£¬K_sP[Cu£¨OH£©₂]=2.2¡Á10^-20£©

Answer 1

·ÖÎö £¨1£©MgCl₂µÄË®ÈÜÒºÖÐþÀë×ÓË®½â£¬ÈÜÒºÏÔËáÐÔ£»
£¨2£©Fe³⁺Ò×Ë®½âÉú³É³Áµí£¬¿Éͨ¹ýµ÷½ÚÈÜÒºpHµÄ·½·¨´Ù½øFe³⁺µÄË®½â£¬×¢Òâ²»ÄÜÒýÈëеÄÔÓÖÊ£»
£¨3£©ÔÚ25¡æÏ£¬Æ½ºâʱÈÜÒºÖÐc£¨NH₄⁺£©=c£¨Cl^-£©=0.005mol/L£¬¸ù¾ÝÎïÁÏÊغãµÃn£¨NH₃£®H₂O£©=£¨0.5a-0.005£©mol/L£¬¸ù¾ÝµçºÉÊغãµÃc£¨H⁺£©=c£¨OH^-£©=10^-7mol/L£¬ÈÜÒº³ÊÖÐÐÔ£»
£¨4£©½áºÏͼʾ¸ù¾ÝË®µÄÀë×Ó»ý±í´ïʽK_w=c£¨H⁺£©•c£¨OH^-£©¼°ÇâÑõ¸ùÀë×ÓŨ¶È¼ÆËã³ö25¡æʱºÍ100¡æË®µÄÀë×Ó»ý£¬Éè³öÇâÑõ»¯±µÈÜÒº¡¢ÑÎËáÈÜÒºµÄÌå»ý£¬È»ºó¸ù¾ÝÈÜÒºµÄpHÁÐʽ¼ÆËã³ö¶þÕßµÄÌå»ý±È£»
£¨5£©ÄÑÈܵç½âÖʵÄÈܶȻýԽС£¬¼ÓÈ백ˮʱԽÒ×Éú³É³Áµí£®

½â´ð ½â£º£¨1£©MgCl₂µÄË®ÈÜÒºÖÐþÀë×ÓË®½â£¬ÈÜÒºÏÔËáÐÔ£¬·´Ó¦µÄÀë×Ó·½³ÌʽΪ£ºMg²⁺+2H₂O?Mg£¨OH£©₂+2H⁺£¬¹Ê´ð°¸Îª£ºË᣻Mg²⁺+2H₂O?Mg£¨OH£©₂+2H⁺£»
£¨2£©FeCl₃Ò×Ë®½âÉú³ÉÇâÑõ»¯Ìú£¬¼ÓÈëMg£¨OH£©₂·ÛÄ©¡¢MgO»òMgCO₃£¬µ÷½ÚÈÜÒºµÄpH£¬´Ù½øÌúÀë×ÓµÄË®½â£¬ÇÒ²»ÒýÈëеÄÔÓÖÊ£¬¹Ê´ð°¸Îª£ºB£»
£¨3£©ÔÚ25¡æÏ£¬Æ½ºâʱÈÜÒºÖÐc£¨NH₄⁺£©=c£¨Cl^-£©=0.005mol/L£¬¸ù¾ÝÎïÁÏÊغãµÃc£¨NH₃£®H₂O£©=£¨0.5a-0.005£©mol/L£¬¸ù¾ÝµçºÉÊغãµÃc£¨H⁺£©=c£¨OH^-£©=10^-7mol/L£¬ÈÜÒº³ÊÖÐÐÔ£¬¹Ê´ð°¸Îª£ºÖУ»
£¨4£©Aµã25¡æʱ£¬c£¨H⁺£©=c£¨OH^-£©=1¡Á10^-7mol/L£¬K_w=c£¨H⁺£©•c£¨OH^-£©=1¡Á10^-7¡Á1¡Á10^-7=10^-14£»
100¡æʱ£¬c£¨H⁺£©=c£¨OH^-£©=1¡Á10^-6mol/L£¬K_w=c£¨H⁺£©•c£¨OH^-£©=1¡Á10^-6¡Á1¡Á10^-6=10^-12£¬
ÉèÇâÑõ»¯±µÈÝÈÜÒºµÄÌå»ýΪxL£¬ÑÎËáµÄÌå»ýΪy£¬pH=8µÄBa£¨OH£©₂ÈÜÒº£¬ÈÜÒºÖÐc£¨OH^-£©=1¡Á10^-6mol/L£¬
pH=5µÄÏ¡ÑÎËáÈÜÒºÖÐc£¨H⁺£©=1¡Á10^-5mol/L£¬
Óûʹ»ìºÏÈÜÒºpH=7£¬±ØÐëÂú×ãn£¨H⁺£©=n£¨OH^-£©£¬¼´1¡Á10^-6mol/L¡ÁxL=1¡Á10^-5mol/L¡ÁyL£¬
½âµÃx£ºy=10£º1£¬
¹Ê´ð°¸Îª£º10^-12£»10£º1£»
£¨5£©ÄÑÈܵç½âÖʵÄÈܶȻýԽС£¬¼ÓÈ백ˮʱԽÒ×Éú³É³Áµí£¬ÔòÉú³ÉµÄ³ÁµíΪCu£¨OH£©₂£¬·´Ó¦µÄÀë×Ó·½³ÌʽΪCu²⁺+2NH₃•H₂O=Cu£¨OH£©₂¡ý+2NH₄⁺£¬
¹Ê´ð°¸Îª£ºCu£¨OH£©₂£»Cu²⁺+2NH₃•H₂O=Cu£¨OH£©₂¡ý+2NH₄⁺£®

µãÆÀ ±¾Ì⿼²éÁËË®µÄµçÀë¼°Ë®µÄÀë×Ó»ýµÄ¼ÆË㣬עÖØÁË»ù´¡ÖªÊ¶µÄ¿¼²é£¬×¢Òâ´¿Ë®ÖÐc£¨H⁺£©=c£¨OH^-£©£¬±¾ÌâÄѶȲ»´ó£®