COD�Ĝy(c��)��ʲô,��

��r(sh��)�g��2008-05-26 15:18 ��Դ�� : ��x��3788

һ,��ԭ��

�ڏ�(qi��ng)��Һ��,��(zh��n)�_��^��t��⛘�(bi��o)��(zh��n)��Һ,��ӟ��,��ˮ��߀ԭ��|(zh��)(��Ҫ��ЙC(j��)��)��^��t��ԇ��F�`��ָʾ��,��၆�F�@��(bi��o)��(zh��n)��Һ�ص�,��(j��)��ĵ��t��⛘�(bi��o)��(zh��n)��Һ��Ӌ(j��)��ˮ�ӻ��W(xu��)��

��,��x��

1,��250mLȫ��b�á�

2,��ӟ��b��(늠t),��

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

��,��ԇ��

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��,��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�С�

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

4,��D��y��Һ��Qȡ5.0g��y��뵽500ml��,��һ��, ��r(sh��)�u��(d��ng)ʹ��ܽ��,��

5��

6,��ṯ��Y(ji��)��ĩ,��

�ġ��(bi��o)����

��(zh��n)�_��ȡ10.00mL��t��⛘�(bi��o)��(zh��n)��Һ��250mL�F��ƿ��,��ˮϡ��110mL��,��30mL��ᣬ�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),��

��,��y(c��)��E

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��ܣ��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��,��ȸ��(j��)�y(c��)�ďUˮ��,��x��ϡጱ��(sh��)��ϡጺ�Uˮ�Н��50��200mg/L��,��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�У��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(c��)��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��

��,��Ӌ(j��)��

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��,��߿ɽj(lu��)��2000mg/L��x�ӝ�ȵ�ˮ�ӡ��x�ӵĝ��^��,��Ҳ��ټ��ṯ,��ʹ��ṯ:��x��=10:1(W/W)��F(xi��n)��Ȼ��Ӱ표y(c��)��,��

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��w�e	0.25000mol/L	H₂SO₄-Ag₂SO₄	HgSO₄	[(NH₄)₂Fe(SO₄)₂]	�ζ�ǰ��
(mL)	K₂Cr₂O₇��Һ��mL��	��Һ��mL��	(g)	(mol/L)	�w�e��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

ˮ��ȡ��ԇ��

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��,��

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��)��,��

6��CODCr�Ĝy(c��)��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�׃��,��

����D(zhu��n)�d��ǳ��ڂ��f��Ϣ֮Ŀ�ġ��Ё�Դ��(bi��o)ע�e(cu��)�`��ַ��ĺϷ��(qu��n)��,��Ո(q��ng)��߳֙�(qu��n)��C��c��W(w��ng)(li��n)ϵ,��҂��r(sh��)��h��,��x�x,��