Answer:
B. Cu + 4HNO3 → Cu(NO3)2 + 2H2O + 2NO2
Explanation:
Hello,
In this case, we should understand oxidizing agents as those substances able to increase the oxidation state of another substance, therefore, in B. reaction we notice that copper oxidation state at the beginning is zero (no bonds are formed) and once it reacts with nitric acid, its oxidation states raises to +2 in copper (II) nitrate, thus, in B. Cu + 4HNO3 → Cu(NO3)2 + 2H2O + 2NO2 nitritc acid is acting as the oxidizing agent.
Moreover, in the other reactions, copper (A.), sodium (C. and D.) remain with the same initial oxidation state, +2 and +1 respectively.
Regards.
It’s true:)
The subscript on chemical equations tells you how many atoms the elements have. If there is no subscript then there is only 1 atom.
Polar will always have the higher boiling point because they have strong van der waal forces
The protons in the atom determine what the atom is. It also determines the atomic number<span>. For example, hydrogen has one proton, so it the atomic number is one. Lithium has an atomic number of three because it has three protons.</span>
