怎么计算0.20摩尔每升的磷酸的ph
\u4e13\u4e1a\u603b\u78f7-\u4ef7\u683c\u516c\u9053-\u70ed\u9500\u8d27\u6e90-\u54c1\u79cd\u9f50\u5168 磷酸的电离常5261数K1=7.6x10^-3,K2=6.3x10^-8K3=4.4x10^-13K2
K3相对K1非常小
就按4102K1计算,设电离的1653H+浓度内为x
H3PO4
=可逆=H++H2PO4-x
x
x溶液中未电离的H3PO4分子浓度为0.2-x根据
电离常数
容计算式K1=cH+
x
cH2PO42-
/
cH3PO4=
x^2
/
0.2-x=7.6x10^-3解得H+浓度x=0.03537molL-PH=1.45
绛旓細纾烽吀鍒嗘瀽绾祿搴︽槸85%銆傜7閰哥殑瀵嗗害鏄1.69锛屾懇灏旇川閲忔槸98锛屽垎鏋愮函娴撳害鏄85%锛璁$畻鍑1000姣崌纾烽吀鐨鎽╁皵鏁板氨鏄祿搴︼細C锛圚3PO4锛=1000*1.69*85%闄や互98=14.7mol姣L銆傜7閰告槸涓绉嶅父瑙佺殑鏃犳満閰革紝鍖栧寮忎负H3PO4锛屽垎瀛愰噺涓97.995锛岀7閰镐笉鏄撴尌鍙戯紝涓嶆槗鍒嗚В锛屽嚑涔庢病鏈夋哀鍖栨э紝鍏锋湁閰哥殑閫氭э紝鏄笁鍏...
绛旓細鍋囪鍩规涓鍗0.02M (20mM) 纾烽吀鐩愮紦鍐叉恫 pH = pKa2 + Log[鎽╁皵(K2HPO4)/鎽╁皵(KH2PO4)]7.0= 7.2 + Log[鎽╁皵(K2HPO4)/鎽╁皵(KH2PO4)]閭d箞,(1)鎽╁皵(K2HPO4)/鎽╁皵(KH2PO4)=10^0.2 鍙堬紝锛2锛夋懇灏(K2HPO4)+ 鎽╁皵(KH2PO4)= 1 x 0.02 = 0.02 鎽╁皵 瑙h仈绔嬫柟绋嬬粍锛1锛...
绛旓細鏍规嵁PH=1/2(PKa+Pc)PKa=2PH-Pc=8-P0.2=8-0.7=7.3
绛旓細1.鎹甈鍘熷瓙瀹堟亽璁$畻闇纾烽吀鐨勭墿璐ㄧ殑閲 ---2鍗囨贩鍚堟恫涓惈P鍘熷瓙0.2mol ---闇瑕佺函纾烽吀0.2mol ---闇瑕4鎽╁皵/鍗嘓3PO4婧舵恫鐨勪綋绉:(0.2mol/4mol/L)*1000=50mL 2.鎹挔绂诲瓙瀹堟亽姹傞渶姘㈡哀鍖栭挔鐨勮川閲 ---2鍗囨贩鍚堟恫涓惈P鍘熷瓙0.2mol(鍓嶉潰鐨勮绠楃粨鏋)---2鍗囨贩鍚堟恫涓惈NaH2PO4鍜孨a2HPO4鐨勬荤墿璐ㄧ殑...
绛旓細濡傛灉閰嶅埗鐨勭7閰婧舵恫涓1鍗囷紝閭d箞闇瑕佺函纾烽吀0.05脳98=4.9鍏嬶紝濡傛灉浣跨敤鐨勬槸85%椋熺敤绾х7閰革紝閭d箞闇瑕佺7閰哥殑璐ㄩ噺鏄4.9/0.85=5.765鍏嬨傚嵆绉板彇5.765鍏85%鐨勭7閰革紝鍦ㄦ悈鎷岀殑鍚屾椂锛屽姞姘村畾瀹硅嚦涓鍗囧嵆鍙
绛旓細鍋囪閰嶅埗500姣崌 杩戜技涓1.32鍏 绉板彇1.32鍏纾烽吀姘簩閾靛浐浣擄紝婧朵簬500姣崌钂搁姘翠腑锛屾悈鎷屽潎鍖鍗冲彲
绛旓細纾烽吀鐨勫惈閲85%鏄釜杩戜技鍊硷紝璁$畻杩囩▼涓簲璇ユ寜85%璁$畻銆傜7閰哥殑瀵嗗害鏄1.69锛屾懇灏旇川閲忔槸98锛屼笉鐭ラ亾瀵嗗害鏃犳硶璁$畻鍑烘懇灏旇川閲忥紝璁$畻鍑1000姣崌纾烽吀鐨勬懇灏鏁板氨鏄祿搴︼細C(H3PO4)=1000*1.69*85%/98=14.7mol/L C(1/3H3PO4)=1000*1.69*85%/(1/3*98)=44mol/L ...
绛旓細鍋囪閰嶄竴鍗100mmol/l 锛堝嵆0.1mol锛弆锛塸h6.0鐨勭7閰缂撳啿娑诧細ph = pka2 + log([hpo42-]/[h2po4-])6.0 = 7.2 + log([hpo42-]/[h2po4-])= 7.2 + log(hpo42-鎽╁皵/h2po4-鎽╁皵)(hpo42-鎽╁皵/h2po4-鎽╁皵)=10^(-1.2)= 0.0631 hpo42-鎽╁皵 + h2po4-鎽╁皵 = 0.1 姹傝В寰...
绛旓細85%浠ヤ笂娴撶7閰稿湪20鎽勬皬搴︽椂鐨勬祿搴︺佸瘑搴﹀鐓ц〃濡備笂銆傚亣瀹氫綘閭g摱娴撶7閰哥殑娴撳害鏄89%锛屾煡琛ㄥ緱89%娴撶7閰哥殑瀵嗗害鏄1.738鍏/姣崌锛屽嵆1738鍏/鍗囷紝宸茬煡纾烽吀鐨勬懇灏璐ㄩ噺鏄98鍏/鎽╋紝鍒89%娴撶7閰哥殑鎽╁皵娴撳害鏄 1738g/L / 98g/mol * 0.89 = 15.7839mol/L ...
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