本题目来源于试卷: Classification of Matter A.1 Periodic Table Elements Classification，类别为 IB化学
[单选题]
The oxidation state ofgsk2ji 4;k-eoo:ut)kpv. a ex9h5z( q Cr does not change in all of the folupfky5+ etb; .lowing except:
A. $CrO_4^{2−}$→$CrOX_3$
B. $CrO_4^{2−}$ →$Cr_2O_7^{2−}$
C. $K_2Cr_2O_7$→$CrO_4^{2−}$
D. $K_2CrO_4$→$Cr_2O_3$
参考答案: D
本题详细解析:
Explanation: The sum of the oxidation state of all atoms in a compound is 0 and in an ion is equal to the charge of the ion.
O in the above molecules have an oxidation state of -2.
Group I elements have an oxidation state of +1.
In choices A, B, and C, the oxidation states of Cr on both sides are +6.
In choice D, the oxidation state of Cr changes from +6 to +3.
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