I assume this is a true or false question. I would say true
K2Cr2O7 + 14HCl → 2CrCl3 + 2KCl + 3Cl2 + 7H2O
the correct option is :
K2Cr2O7, because the oxidation number of Cr changes from +6 to +3.
<u>Oxidation number of Cr in K2Cr2O7 is:</u>
K2Cr2O7 = 2K + 2 Cr + 7 O
= 2(+1) + 2Cr + 7(-2)
= 2 + 2Cr -14
[total charge on K2Cr2O7 = 0], Hence;
2 + 2Cr -14 = 0
2Cr -12 = 0
2Cr = 12
Cr = 12/2
<u>Cr = +6</u>
<u>Oxidation number of Cr in CrCl3 is:</u>
CrCl3 = Cr + 3Cl = 0
Cr + 3(-1) = 0
Cr -3 = 0
<u>Cr = +3</u>
Hence Cr is changing its oxidation number from
+6 in K2Cr2O7 to +3 in CrCl3.
Since the oxidation number of Cr [ +6 → +3] is decreasing here,
Cr is getting reduced.
so K2Cr2O7 is an oxidizing agent,as it is getting itself reduced and oxidizes others.
Answer:
A: isotopes
Explanation:
Hello.
In this case, since isotopes are defined as atoms of the same element with the same atomic number (number of protons and electrons) but different mass number (atomic mass) we can represent them via the symbol of the element followed by a dash indicating the atomic mass of the occurring isotope, for instance, for carbon, we may find C-12, C-13 and even C-14 which is useful in dating techniques.
Therefore, Lithium-4 or Li-4 and Lithium-5 or Li-5 can be defined as isotopes.
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