Final answer:
The compound MgBr2 is correctly named magnesium dibromide, not magnesium bromate. The metal retains its name, and the non-metal's name ends with the suffix '-ide.' For 0.2 moles of magnesium dibromide, there are 0.2 moles of magnesium ions and 0.4 moles of bromide ions.
Step-by-step explanation:
The compound MgBr2 is correctly named as magnesium dibromide. This is because the compound consists of magnesium ions (Mg2+) and bromide ions (Br−). In naming ionic compounds, the metal (magnesium in this case) keeps its name and is followed by the name of the non-metal (bromine), modified to have an 'ide' suffix as in 'bromide'. The 'di' in dibromide indicates that there are two bromide ions for each magnesium ion. Hence, for a sample of 0.2 moles of magnesium dibromide, you would have:
- 0.2 moles of Mg2+ ions
- 0.4 moles of Br− ions (because there are two bromide ions for every one magnesium ion)