Tutor profile: Alvaro R.
Questions
Subject: Inorganic Chemistry
Compare the Ionization energy (IE) of Phosphorus and Sulfur in terms of e- repulsion and half-filled stability?
IE is the energy required to remove an electron from a gaseous isolated atom. From left to right of periodic table, IE generally increases. So we might think P < S However, looking closely at the electron configuration will help us answering this question P (with 15 electrons) 1s2 2s2 2p6 3s2 3px1 3py1 3pz1 S (with 16 electrons) 1s2 2s2 2p6 3s2 3px2 3py1 3pz1 We showed here the three degenerate orbitals of 3p: 3px 3py 3pz There will be less energy required to remove an electron in S than in P because of electron pair repulsion present in S (3px2). Another factor is the change of stability once electron is removed. You will therefore have a half-filled orbitals for S (3px1 3py1 3pz1) compared to P which will produce a partially filled orbitals (3px1 3py1 3pz0). Hence, the answer is P > S.
Subject: Chemistry
What is the ground state electron configuration of Copper?
Following the Aufbau Principle, "building-up" or filling up the orbitals should start from the lowest orbital up to highest orbital until all electrons are accounted. Cu has 29 electrons You will get 1s2 2s2 2p6 3s2 3p6 4s2 3d9 However we have to consider the energy level of 3d as being lower than 4s. So we have, 1s2 2s2 2p6 3s2 3p6 3d9 4s2 We also need into account the stability rule: Half-filled orbital > fully-filled orbital > partially-filled orbital and therefore we will arrived with the final answer 1s2 2s2 2p6 3s2 3p6 3d10 4s1
Subject: Basic Chemistry
What is the net ionic equation for the aqueous solution of Sodium hydroxide and Hydrochloric Acid initially at room temperature?
A neutralization reaction is when an acid and a base react to form a salt and water. So when hydrochloric acid reacts with sodium hydroxide, we have the formation of Sodium chloride and water, NaOH(aq) + HCl(aq) -> NaCl(aq) + H2O(l) The complete net ionic equation will be Na^+ (aq) + OH^- (aq) + H^+ (aq) + Cl^-(aq) -> H2O(l) + Na^+ (aq) + Cl^- (aq). Note: ^ means charge of the ion