How many grams of MgBr2 are needed to create 3.0L of a 4.5M aqueous solution of magnesium bromide?

Mike and mitchell decide to have a foot race. they mark off a stretch of 100 yards, and recruit cindy to work the stopwatch. after running the race and looking at the results, cindy declared that mitchell was the fastest. so how did the boys times compare?

Which statement best describes what happens when molecular compounds melt

What is the molarity of the solution produced when 145 g of nacl is dissolved in sufficient water to prepare 2.75 l of solution?