A swimming pool contains 155m3 of water. If water must be heated from 16C to 32C. How many Joules of heat energy must be supplied?

1 cal=4.184 J
Do I need to convert 155m3 to weight?

yes. Then
mass x 4.184 J/g*c x (Tfinal-Tinitial)= heat energy required.

Yes DrBob, my problem is how to convert 155m3 of water to weight unit (?)

You can go two routes. The quickest is to go to www.google.com and type in 155 cubic meters to cubic centimeters. Hit enter and you will have the answer. That will be the number of grams since we will assume the density of water is 1 g/cc.
OR you can do the conversion yourself.
1 meter = 100 cm; therefore,
1 cubic meter = 100 cm x 100 cm x 100 cm = 1 x 10^6 cc.
Thus 155 m^3= ??
I hope this helps.

Thanks for teaching me how to do it. I'll do the work.

Its always better to know how to do it.

identify the solute and solvent in a hot chocolate solution that is made of chocolate syrup and warm milk

Actually, there are no right and wrong answers regarding solute and solvent. Usually, however, the material in the larger amount is called the solvent and the other is the solute. Of if a solid and a liquid, then the liquid is the solvent and the solid is the solute. In this case, milk is the greater part of the mix and chocolate syrup is the smaller; therefore, I would call milk the solvent and choc syrup the solute.

BTW, it would be better to post a seprate question instead of piggy backing on another. That way you get the emails and we are more likely to see your post. I just happened to be reviewing the board when I saw your post. To post a separate question, go to the top of this page and click on Post a New Question. Then let 'er rip.

In a hot chocolate solution made of chocolate syrup and warm milk, the solvent is the warm milk and the solute is the chocolate syrup. The milk is the larger part of the mixture and acts as the liquid that dissolves or disperses the chocolate syrup. It is important to note that there are no strict rules for determining the solute and solvent, but the material in the larger amount is typically considered the solvent.