Which set up would correctly complete the work for determining how many moles of NaOH will be produced if 10.5 grams of water (H2O) is used?

Can someone me with 1 to 4 plz. fast

How many grams of mgbr2 are needed to produce 75g or metal?

Astudent pours 10.0 g of salt into a container of water and observes the amount of time it takes for the salt to dissolve. she then repeats the process using the same amounts of salt and water but this time she slowly stirs the mixture while it is dissolving. the student performs the experiment one more time but this time she stirs the mixture rapidly. the dependent variable in this experiment is: time for salt to dissolve speed of stirring amount of water mass of salt