Which of these mixtures are heterogeneous? 1.brass (an alloy of copper and zinc) 2.granite (a type of rock with multicolor spots) 3.oil and water 4.salt and water

Given sno2 + 2h2 - sn + 2h20 tin oxide reacts with hydrogen to produce tin and water. how many moles of sno2 are needed to produce 500.0 grams of sn?

Assuming complete dissociation of the solute, how many grams of kno3 must be added to 275 ml of water to produce a solution that freezes at -14.5 c? the freezing point for pure water is 0.0 c and k_f is equal to 1.86 c/m

The atoms of a solid aluminum can are close together, vibrating in a rigid structure. if the can is warmed up on a hot plate, what happens to the atoms?