Question

³£ÎÂÏ£¬Ïò20mL 0.2mol/L H₂AÈÜÒºÖеμÓ0.2mol/L NaOHÈÜÒº£®ÓйØ΢Á£µÄÎïÖʵÄÁ¿±ä»¯Èçͼ£¨ÆäÖТñ´ú±íH₂A£¬¢ò´ú±íHA^-£¬¢ó´ú±íA^2-£©Ëùʾ£®¸ù¾ÝͼʾÅжϣ¬ÏÂÁÐ˵·¨ÕýÈ·µÄÊÇ£¨¡¡¡¡£©

• A¡¢µ±V£¨NaOH£©=20mLʱ£¬ÈÜÒºÖÐÀë×ÓŨ¶È´óС¹Øϵ£ºc£¨Na⁺£©£¾c£¨HA^-£©£¾c£¨A^2-£©£¾c£¨H⁺£©£¾c£¨OH^-£©
• B¡¢µÈŨ¶ÈµÄNaOHÈÜÒºÓëH₂AÈÜÒº°´2£º1»ìºÏºó£¬ÆäÈÜÒºÖÐË®µÄµçÀë³Ì¶È±È´¿Ë®Ð¡
• C¡¢NaHAÈÜÒºÖУºc£¨OH^-£©+c£¨A^2-£©=c£¨H⁺£©+c£¨H₂A£©
• D¡¢ÏòÉÏÊö¼ÓÈë20mL NaOHÈÜÒººóËùµÃÈÜÒºÖÐÔÙ¼ÓÈëË®µÄ¹ý³ÌÖУ¬pH¿ÉÄܼõÉÙ

Answer 1

¿¼µã£ºËá¼î»ìºÏʱµÄ¶¨ÐÔÅжϼ°ÓйØphµÄ¼ÆËã

רÌ⣺µçÀëƽºâÓëÈÜÒºµÄpHרÌâ

·ÖÎö£ºA£®¸ù¾ÝͼÏóÖª£¬µ±V£¨NaOH£©=20ʱ£¬·¢Éú·´Ó¦ÎªNaOH+H₂A¨TNaHA+H₂O£¬ÈÜÒºÖ÷ҪΪNaHA£¬µçÀëΪÖ÷£¬ÈÜÒºÏÔËáÐÔ£»
B£®Ëá»ò¼îÒÖÖÆË®µçÀ룬º¬ÓÐÈõ¸ùÀë×ÓµÄÑδٽøË®µçÀ룻
C£®¸ù¾ÝÎïÁÏÊغãºÍµçºÉÊغãÅжϣ»
D£®¶þÕßÇ¡ºÃ·´Ó¦Éú³ÉNaHA£¬¼ÓˮϡÊÍHA^-µçÀëºÍË®½â£®

½â´ð£º ½â£ºA£®¸ù¾ÝͼÏóÖª£¬µ±V£¨NaOH£©=20 mLʱ£¬·¢Éú·´Ó¦ÎªNaOH+H₂A¨TNaHA+H₂O£¬ÈÜÖÊÖ÷ҪΪNaHA£¬HA^-µçÀë³Ì¶È´óÓÚË®½â³Ì¶È£¬ÈÜÒºÏÔËáÐÔ£¬Ë®ºÍHA^-¶¼µçÀë³öÇâÀë×Ó£¬Ö»ÓÐHA^-µçÀë³öA^2-£¬ËùÒÔÀë×ÓŨ¶È´óС˳ÐòÊÇc£¨Na⁺£©£¾c£¨HA^-£©£¾c£¨H⁺£©£¾c£¨A^2-£©£¾c£¨OH^-£©£¬¹ÊA´íÎó£»
B£®µÈŨ¶ÈµÄNaOHÈÜÒºÓëH₂AÈÜÒº°´Ìå»ý2£º1»ìºÏºó£¬¶þÕßÇ¡ºÃ·´Ó¦Éú³ÉNa₂AºÍË®£¬Na₂AÊÇÇ¿¼îÈõËáÑδٽøË®µçÀ룬¹ÊB´íÎó£»
C£®¸ù¾ÝµçºÉÊغãµÃc£¨OH^-£©+2c£¨A^2-£©+c£¨HA^-£©=c£¨H⁺£©+c£¨Na⁺£©£¬¸ù¾ÝÎïÁÏÊغãµÃc£¨Na⁺£©=c£¨HA^-£©+c£¨H₂A£©+c£¨A^2-£©£¬ËùÒÔµÃc£¨OH^-£©+c£¨A^2-£©=c£¨H⁺£©+c£¨H₂A£©£¬¹ÊCÕýÈ·£»
D£®¶þÕßÇ¡ºÃ·´Ó¦Éú³ÉNaHA£¬´ËʱÈÜÒº³ÊËáÐÔ£¬¼ÓˮϡÊÍÏÔÐÔÀë×ÓŨ¶È±äС£¬ÒþÐÔÀë×ÓÇâÑõ¸ùÀë×ÓŨ¶ÈÔö´ó£¬ËùÒÔpHÔö´ó£¬¹ÊD´íÎó£»
¹ÊÑ¡£ºC£®

µãÆÀ£º±¾Ì⿼²éËá¼î»ìºÏÈÜÒº¶¨ÐÔÅжϣ¬Ã÷ȷͼÏóÖÐËá¼î»ìºÏʱÈÜÒºÖеÄÈÜÖÊÊǽâ´ð±¾ÌâµÄ¹Ø¼ü£¬×¥×¡Í¼Ïó½øÐзÖÎö¼´¿É£¬ÌâÄ¿ÄѶÈÖеȣ®