My science project is due tuesday. (i know i know i should have done this earlier) Well i really need help with my independent variable as well as my dependent and controlled variables.
My project is:
Will an ice cube melt faster with salt or sugar.
It says that i should only have one independent variable. But there can be more variables on my dependent and controlled variables. I'm just so confused!! If you could please help me that'd be great. Thanks !|||Given that you are investigating "rates of melting", it makes sense in your case that time might be an appropriate choice of an independent variable.
Examples of dependent variables could be temperature, mass of your ice cube, amount of sugar, amount of salt, amount of water.
Also as an example, you can control the amount of water, sugar, salt.
You can also control the starting temperature of your sugar or salt solution.|||Time is the dependent variable because that's the variable that you're trying to determine (which melts faster), not the one that you're controlling. Salt and sugar can be considered as categorical independent variables, if you wish.
Since melting point is a function of the number of molecules of solute in a given volume of water, you know ahead of time that a given weight of salt will melt ice faster than a given weight of sugar. That's because a given weight of salt contains many more molecules than a given weight of sugar. One mole (molecular weight in a liter) of salt is 55 grams (23 g of sodium, 32 grams of chlorine), and that contains 6.02 x 10^23 molecules. One mole of sucrose (table sugar) is 518 g (144 g of carbon, 22 g of hydrogen, 352 g of oxygen), and that contains 60.2 x 10^23 molecules. So to get the same number of molecules in your two treatments, you could use 10 g of salt and 94 g of sucrose.
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