[求助] 求助.硝酸银标准溶液的标定方法 [复制链接]

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硝酸银标准溶液的配制和标定（依据国标GB/T5009.1-2003）šBÙóÐG¢bbs.3c3t.comùz !œHÁ b»
šBÙóÐG¢bbs.3c3t.comùz !œHÁ b»
一、硝酸银标准溶液的配制：šBÙóÐG¢bbs.3c3t.comùz !œHÁ b»
硝酸银溶液：šBÙóÐG¢bbs.3c3t.comùz !œHÁ b»
称取17.5 g硝酸银，溶于1000mL水中，摇匀，溶液保存于棕色瓶中。šBÙóÐG¢bbs.3c3t.comùz !œHÁ b»
淀粉指示液：šBÙóÐG¢bbs.3c3t.comùz !œHÁ b»
称取0.5g可溶性淀粉，加入约5mL水，搅匀后缓缓倾入100mL沸水中，随加随搅拌，煮沸2min，放冷，备用。此指示液应临用时配制。šBÙóÐG¢bbs.3c3t.comùz !œHÁ b»
荧光黄指示液：šBÙóÐG¢bbs.3c3t.comùz !œHÁ b»
称取0.5g荧光黄，用乙醇溶解并稀释至100mL。šBÙóÐG¢bbs.3c3t.comùz !œHÁ b»
二、硝酸银标准溶液的标定：šBÙóÐG¢bbs.3c3t.comùz !œHÁ b»
1.测定方法：šBÙóÐG¢bbs.3c3t.comùz !œHÁ b»
称取0.2g于270。C干燥至质量恒定的基准氯化钠（称准至0.0001g），溶于50mL水中使之溶解，加入5mL淀粉指示液，边摇动边用AgNO3标准溶液滴定，避光滴定，近终点时，加入3滴荧光黄指示液，继续滴定混浊液由黄色变为粉红色为终点。šBÙóÐG¢bbs.3c3t.comùz !œHÁ b»
平行测定三次，同时作空白试验。šBÙóÐG¢bbs.3c3t.comùz !œHÁ b»
2.计算：硝酸银标准溶液的浓度按下式计算：šBÙóÐG¢bbs.3c3t.comùz !œHÁ b»
šBÙóÐG¢bbs.3c3t.comùz !œHÁ b»
   C（AgNO3）= M / (（V—V0）×0.05844)šBÙóÐG¢bbs.3c3t.comùz !œHÁ b»
式中：C（AgNO3）——硝酸银标准溶液之物质的浓度，mol/L；šBÙóÐG¢bbs.3c3t.comùz !œHÁ b»
M——氯化钠之质量，g；šBÙóÐG¢bbs.3c3t.comùz !œHÁ b»
V——滴定硝酸银溶液之用量，mL；šBÙóÐG¢bbs.3c3t.comùz !œHÁ b»
V0——空白试验消耗硝酸银之用量；šBÙóÐG¢bbs.3c3t.comùz !œHÁ b»
0.05844——氯化钠的摩尔质量，Kg/ mol。šBÙóÐG¢bbs.3c3t.comùz !œHÁ b»
šBÙóÐG¢bbs.3c3t.comùz !œHÁ b»
三、注意事项 šBÙóÐG¢bbs.3c3t.comùz !œHÁ b»
šBÙóÐG¢bbs.3c3t.comùz !œHÁ b»
在良好保存条件下溶液有效期为三个月，超过有效期应重新标定。šBÙóÐG¢bbs.3c3t.comùz !œHÁ b»