The correct option is B Cl2O7>SO3>P4O10
Acidic strength is directly propertional to the oxidation state
(A)
Cl2O7:2x+7(−2)=0⇒x=142=+7
SO3:x+3(−2)=0
⇒x=+6
P4O10:4x+10(−2)=0
⇒4x=20
⇒x=+5
Acidic strength order will be Cl2O7>SO3>P4O10
(B)
CO2:x+2(−2)=0
⇒x=+4
N2O5:2x+5(−2)=0
⇒x=102=+5
SO3:x−6=0⇒x=+6
(C)
Na2O:2(x)+(−2)=0
⇒x=+1
MgO:x−2=0⇒x=+2
Al2O3:2x+3(−2)=0
⇒x=62=+3
Acidic strength order Al2O3>MgO>Na2O
(D)
K2O:2(x)+(−2)=0
⇒x=+1
CaO:Oxidation state of Ca=+2
MgO:Oxidation state of Mg=+2
Acidic strength:CaO≈MgO>K2O
Hence, Correct option is (A)