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1��500mLȫ��b��,��

2��ӟ��b��(늠t),��

3��25mL��50mL��ʽ�ζ��ܡ��F��ƿ,��Һ��,��ƿ�ȡ�

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1��t��⛘�(bi��o)��(zh��n)��Һ(c1/6K2Cr2O7=0.2500mol/L),��Qȡ�A(y��)��120��2h�Ļ��(zh��n)��(y��u)�|(zh��)��t��12.258g��ˮ�У��1000mL��ƿ,��ϡ��(bi��o)��,��u��

2��ԇ��F�`ָʾҺ��Qȡ1.485g��_��(C12H8N2·H2O)0.695g��၆�F(FeSO4·7H2O)��ˮ��,��ϡ��100mL,�A��ɫƿ��,��

3��၆�F�@��(bi��o)��(zh��n)��Һ[c(NH4)2Fe(SO4)2·6H2O≈0.1mol/L]��Qȡ39.5g��၆�F�@��ˮ�У�߅��߅��20mL��,��s��1000mL��ƿ��,��ˮϡ��(bi��o)��u��,��R��ǰ,��t��⛘�(bi��o)��(zh��n)��Һ��(bi��o)��

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��(zh��n)�_��ȡ10.00mL��t��⛘�(bi��o)��(zh��n)��Һ��500mL�F��ƿ��,��ˮϡ��110mL��ң��30mL��,��u��,��s�󣬼��3��ԇ��F�`ָʾҺ(�s0.15mL),��၆�F�@��Һ�ζ�,��Һ��ɫ��Sɫ��(j��ng)�{(l��n)�Gɫ��t��ɫ��K�c(di��n)��

C=(0.2500×10.00)/V

ʽ�У�C——��၆�F�@��(bi��o)��(zh��n)��Һ�ĝ��(mol/L),��

V——��၆�F�@��(bi��o)��(zh��n)��Һ��(mL),��

4��-��y��Һ��500mL��м��5g��y��1—2d,��r(sh��)�u��(d��ng)ʹ��ܽ�,��

5��ṯ��Y(ji��)��ĩ,��

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1��ȡ20.00mL��Ͼ��ˮ�ӣ��m��ˮ��ϡ��20.00mL��250mLĥ�ڵĻ��F��ƿ��,��(zh��n)�_��10mL ��t��⛘�(bi��o)��(zh��n)��Һ��(sh��)��С��ʯ��B��ĥ�ڻ��,��Ͽ��ؼ��30mL��-��y��Һ,��p�p�u��(d��ng)�F��ƿʹ��Һ��򣬼ӟ��2h(��_ʼ��vӋ(j��)�r(sh��)),��

��(du��)�ڻ��W(xu��)��ߵďUˮ��,��ȡ��w�e��1/10�ďUˮ�Ӻ�ԇ��15×150mmӲ�|(zh��)��ԇ��У��u��,��ӟ��^��Ƿ�ʾGɫ,��Һ�ʾGɫ��m��(d��ng)�p�ُUˮȡ��,��ֱ��Һ��׃�Gɫ��ֹ,��Ķ��_��Uˮ�ӷ��r(sh��)��(y��ng)ȡ�õ��w�e��ϡጕr(sh��),��ȡ�Uˮ��5mL,��W(xu��)��ܸߣ��t�Uˮ�ӑ�(y��ng)��ϡ�,��Uˮ��x�Ӻ��^30mg/L�r(sh��)��(y��ng)�Ȱ�0.4g��ṯ��F��ƿ��,��ټ��20.00mL�Uˮ��m��Uˮϡ��20.00mL��u��,��

2��s��90.00mLˮ�_ϴ��ܱ�,��ȡ��F��ƿ,��Һ��w�e��140mL��t��̫��,��ζ��K�c(di��n)��@��

3��Һ�ٶ��s��,��3��ԇ��F�`ָʾҺ,��၆�F�@��(bi��o)��(zh��n)��Һ�ζ�,��Һ��ɫ��Sɫ��(j��ng)�{(l��n)�Gɫ��t��ɫ��K�c(di��n)��ӛ��၆�F�@��(bi��o)��(zh��n)��Һ��,��

4��y��ˮ�ӵ�ͬ�r(sh��),��ȡ20.00mL��sˮ��ͬ�Ӳ��E��հ׌�(sh��)�(y��n),��ӛ䛵ζ��հוr(sh��)��၆�F�@��(bi��o)��(zh��n)��Һ��

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CODCr(O2,��mg/L)=8×1000(V0-V1)·C/V

ʽ�У�C——��၆�F�@��(bi��o)��(zh��n)��Һ�ĝ��(mol/L)��

V0——�ζ��հוr(sh��)��၆�F�@��(bi��o)��(zh��n)��Һ��(mL),��

V1——�ζ�ˮ�ӕr(sh��)��၆�F�@��(bi��o)��(zh��n)��Һ��(mL),��

V——ˮ�ӵ��w�e(mL)��

8——��1/2O��Ħ��|(zh��)��g/mol��,��

ע��(xi��ng)

1��ʹ��0.4g��ṯ�j(lu��)��x�ӵ��_(d��)40mg,��ȡ��20.00mLˮ�ӣ��߿ɽj(lu��)��2000mg/L��x�ӝ�ȵ�ˮ��,��x�ӵĝ��^��,��Ҳ��ټ��ṯ��ʹ��ṯ:��x��=10:1(W/W),��F(xi��n)��Ȼ��,��Ӱ표y��

2��ˮ��ȡ��w�e��10.00—50.00mL��(n��i),��ԇ��谴�±��M(j��n)��(y��ng)�{(di��o)��,��Ҳ�ɵõ��M��ĽY(ji��)��

ˮ��ȡ��ԇ��

ˮ ��	0.25000mol/L	H₂SO₄-Ag₂SO₄	HgSO₄	[(NH₄)₂Fe(SO₄)₂]	�ζ�ǰ��w�e
�w �e	K₂Cr₂O₇��Һ	��Һ	(g)	(mol/L)	��mL��
(mL)	��mL��	��mL��	��	��	��
10	5	15	0.2	0.05	70
20	10	30	0.4	0.1	140
30	15	45	0.6	0.15	210
40	20	60	0.8	0.2	280
50	25	75	1	0.25	350

3��(du��)�ڻ��W(xu��)��С��50mg/L��ˮ��,��(y��ng)��0.0250mol/L��t��⛘�(bi��o)��(zh��n)��Һ,��صΕr(sh��)��0.01mol/L��၆�F�@��(bi��o)��(zh��n)��Һ,��

4��ˮ�Ӽӟ��,��Һ��t��ʣ��(y��ng)��1/5—4/5��ˡ�

5��⛘�(bi��o)��(zh��n)��Һ�z��ԇ��|(zh��)��Ͳ��g(sh��)�r(sh��),��ÿ��⛵��ՓCODCr��1.176g,��ܽ�0.4251g��(HOOCC6H4COOK)��sˮ��,��D(zhu��n)��1000mL��ƿ��sˮϡ��(bi��o)��,��ʹ֮�ɞ�500mg/L��CODcr��(bi��o)��(zh��n)��Һ,��Õr(sh��)��䡣

6��CODCr�Ĝy��Y(ji��)��(y��ng)��λ��Ч��(sh��)�֡�

7��ÿ�Ό�(sh��)�(y��n)�r(sh��),��(y��ng)��(du��)��၆�F�@��(bi��o)��(zh��n)�ζ��Һ�M(j��n)�И�(bi��o)��,��Ҝ��^�ߕr(sh��)��ע��ȵ�׃��

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