Number 9 adding oil lubricates the chain making it easier to pedal. Also the oil prevents rusting
Answer:
Ag⁺(aq) + Cl⁻(aq) ==> AgCl(s)
Explanation:
The net ionic equation can be described as the equation that contains only those species which would be participated in the chemical reaction. The spectator ions are the type of the ions that are present in both sides of the chemical equation these ions could not be present in the net ionic equation
First, it is easiest if you write the compete molecular equation:
AgNO₃(aq) + KCl(aq) ⇔ AgCl(s) + KNO₃(aq)
we look up which compounds are soluble (aq) and which are not (s). In this case, silver chloride (AgCl) is not soluble. Thus, the net ionic equation is...
Ag⁺(aq) + Cl⁻(aq) ==> AgCl(s)
Chemists use balanced chemical equations as a basis to calculate how much reactant is needed or how much product will be formed in a reaction.
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.
Hello Gary!
*Sorry if I'm late*
Your answer is going to be 65.
Element A (which is actually Zinc) has the atomic number of 65. (I remember having got memorize this also).
Pretty much the explanation is that the number of patrons is equivalent to the element's atomic number!
Hope this helps!
Have a nice day :D
