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4H2CrO4+6NaHSO3+3H2SO4=2Cr2(SO4)3+3Na2SO4+10H2O

2H2CrO4+3Na2SO3+3H2SO4= Cr2(SO4)3+3Na2SO4+5H2O

߀ԭ��NaOH�к��pH=7��8,��ʹCr3+��Cr(OH)3��

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Ͷ�ϱȲ��(y��ng)�^��,��t��Mˎ��,��Ҳ��[Cr2(OH)2SO3]2-��;

�� ߀ԭ��(y��ng)�r�g�s��30min;

�� t��pH��7��8��턩��ʯ��,��̼��c��c,��ɸ��(j��)��H��r�x�á�

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H2Cr2O7+6FeSO4+6H2SO4=Cr2(SO4)3+3Fe 2(SO4)3+7H2O

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�� Uˮ��r�t��Ȟ�50��100mg/L;

�� ߀ԭ�r�Uˮ��pH=1��3;

�� ߀ԭ��һ��Cr6+�� FeSO4·7H2O=1��25��30

�� (y��ng)�r�g��С��30min

�� кͳ��pH��7��9

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�� ၆�FͶ��FeSO4·7H2O��CrO3=16��1;

�� NaOH��pH=8��9;

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ˮ��N2H4·H2O��Ի�΢�A�ԗl��£��Ѹ�ٵ�߀ԭ��r�t��ɚ��t��,��

4CrO3+3N2H4=4Cr(OH)3+3N2

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2,��늽ⷨ

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�� t�UˮCr6+��Ȟ�50��200mg/L;

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