Equimolar amounts of Cl2(g) and CO(g) are injected into an evacuated, rigid container, where they react according to the equation below. Cl2(g)+CO(g)⇄COCl2(g) ΔHrxn=−109kJ/molrxn (a) If 7.0 g of CO(g) is consumed in the reaction with excess Cl2(g), how many moles of COCl2(g) are produced? (b) Which element is oxidized in this reaction? Justify your answer in terms of oxidation numbers.

0.25 moles of COCl₂ are been produced

The element that is oxidized is C, it changed the oxidation state from +2 in CO to +4 in phosgene.

Explanation:

Equilibrium reaction:

Cl₂(g)  +  CO(g)  ⇄  COCl₂(g)

Let's convert the mass of CO to moles:

7g . 1mol /28g = 0.25 moles

As ratio is 1:1, we can say that 0.25 moles of COCl₂ are been produced.

1 mol of chlorine reacts to 1 mol of carbon monoxide in order to produce 1 mol of phosgene.

Chlorine is been reduced:

Cl₂  +  2e⁻  ⇄  2Cl⁻

Change the oxidation state, from 0 (ground state) to -1. Oxidation state decreased.

Carbon is been oxidized.

In CO, carbon has +2 as oxidation state. In phosgene the oxidation state is +4. This oxidation state was increased, that's why it has oxidized.

assuming that your periodic table has eighteen columns, you should highlight   the four elements in the third column from the left of the table.

neutral atoms of elements after calcium contain d electrons. the energy of d orbitals of a particular main shell lies between the energy of the s and p orbitals of the next main shell. for example, electrons in the have energy higher than those in the orbital while lower than those of the orbital.

by the aufbau principle, electrons fill orbitals one at a time, starting from those of the lowest energy. the orbital is therefore filled right after orbitals and before orbitals.  

potassium has electron configuration and calcium . the s orbital of a main shell holds a maximum of two electrons. the next element would thus have the electron configuration and satisfy the requirements.

a neutral atom of the element contains three electrons on top of the most recent noble gas element. it should thus be placed in the third column of the periodic table. both scandium and yttrium would satisfy the conditions. an aufbau diagram indicates that the 4f orbital is filled before the 5d. however, it appears that exceptions exists for both lanthanum and actinium. neutral atoms of the two d-block elements also demonstrate the and should be highlighted as well.

the answer is c. nacl