Question

Rocco needs to make two compounds for an experiment he is performing, Lithium Chloride (LiCl) and Magnesium Bromide (MgBr2). Both compounds are formed using the following chemical reactions:

Li + Cl -> LiCl + Heat
Mg + Br -> MgBr2 + Heat

When Rocco prepares these compounds, he always uses the SAME AMOUNT of halogen but notices that he only ends up with much less magnesium compound compared to lithium compound. Answer the following

1) Is Rocco making or breaking bonds when he prepares these compounds? Provide 2 pieces of evidence for this

2) What type of bond occurs in these compounds, provide 2 pieces of evidence for bond type

3) Using your knowledge of oxidation numbers, explain WHY Rocco is only getting half as much magnesium compound than lithium compound when preparing these chemicals. What SHOULD Rocco do to increase his yield?

Answer 1

Step-by-step explanation:

Rocco is making bonds when he prepares these compounds. Two pieces of evidence for this are:

The chemical reactions are written with an arrow pointing to the right, indicating that the reactants are being converted into products.

The reactions release heat, which is a sign of a chemical reaction occurring and bonds forming.

The bond type in these compounds is an ionic bond. Two pieces of evidence for this are:

The reactants in the chemical reactions consist of a metal (Li or Mg) and a nonmetal (Cl or Br), which are the types of elements that typically form ionic bonds.

The products of the reactions are compounds with a metal and a nonmetal, which also suggests an ionic bond.

The oxidation numbers of lithium and magnesium are +1 and +2 respectively. The oxidation number of chlorine and bromine are -1. Since the oxidation number of lithium is lower than the oxidation number of magnesium, lithium will lose an electron more easily than magnesium. So the reaction of lithium and chlorine is more favorable than magnesium and bromine. That's why Rocco is only getting half as much magnesium compound than lithium compound when preparing these chemicals. To increase his yield, Rocco can try to use a higher amount of magnesium or a lower amount of bromine in the reaction.