Answer:
(V) 1s 2 2s 2 2p 6 3s 2 3p 5
Explanation:
Electron Affinity can be defined as the energy associated with a neutral atom, when an electron is added to form a negative ion.
1s 2 2s 2 2p 6 3s 2 3p 5 , is the electronic configuration of Chlorine.
The electron affinity is positive because it is an exorthermic reaction, meaning that, energy was released during the addition of an electron to the atom.
Cl (g) + e- -------> Cl- (g) = -349KJ/mol
Answer:
P= 0.87g/mL or 0.87g/cm^3
Explanation:
P=m/v
P=density
P=17.4g/20mL
P= 0.87g/mL
1mL=1cm^3
This is an oxidation reduction reaction
oxidation happens when the species gives out electrons.Oxidation state of the element Cu increases from 0 to +2
Cu ---> Cu²⁺ +2e --1)
Reduction happens when the species gains electrons.
Oxidation state of N reduces from +5 to +2
4H⁺ + NO₃⁻ + 3e ---> NO + 2H₂O --2)
To balance the reactions, number of electrons need to be balanced.
Multiply 1st reaction by 3
Multiply 2nd reaction by 2
3Cu ---> 3Cu²⁺ + 6e
8H⁺ + 2NO₃⁻ + 6e ---> 2NO + 4H₂O
add the 2 equations
3Cu + 8H⁺ + 2NO₃⁻ --> 3Cu²⁺ + 2NO + 4H₂O
add 6NO₃⁻ ions to each side
3Cu + 8HNO₃ --> 3Cu(NO₃)₂ + 2NO + 4H₂O
the balanced redox reaction equation is as follows;
3Cu(s) + 8HNO₃(aq) --> 3Cu(NO₃)₂ (aq)+ 2NO(g) + 4H₂O(l)
