Hi guys I really need help with question 3,4 and 5 I should submit it tomorrow. Thanks!

Which diagram shows the correct way to represent an ionic compound of magnesium oxide?

Draw the structure for 5-isopropyl-2-methyl-3-nonene

Hydrogenation reactions, in which h2 and an "unsaturated" organic compound combine, are used in the food, fuel, and polymer industries. in the simplest case, ethene (c2h4) and h2 form ethane (c2h6). if 140 kj is given off per mole of c2h4 reacting, how much heat (in mj) is released when 12 kg of c2h6 forms?