A student wants to remove the salt from a mixture of sand and salt in order to get only pure sand. He adds water to the mixture.
Why is this step helpful? A Salt dissolves in water.
B Sand dissolves in water.
C The water freezes to the salt.
D The salt floats on top of the water.
Here is one way: Add water to the mixture. Only the sugar dissolves. This is a physical change.
Explanation:
The sugar would dissolve in water. You could then pour off the solution and wash the remaining sand with a bit more water. Heat the water to evaporate it from the sugar, and the two are separated.
So grams = mols*MolarMass. Here, MolarMass (MM) = 105.99g which can be found using the periodic table. mols is given to be 0.802. We can then plug in to get that it corresponds to 85.0g.
