Your teacher give you a bag of white powder with 0.396 moles written on it. You weigh the white powder and the scale says 80.0 g. Your teacher tells you that is one of the substances below. What is the substance? NaCl (table salt)

NaHCO3 (baking soda)

Na2B4O7 (borax)

6. using 3 – 4 sentences explain (in your own words) why water expands when it freezes? 7. using your knowledge of colligative properties explain whether sodium chloride or calcium chloride would be a more effective substance to melt the ice on a slick sidewalk. use 3 – 4 sentences in your explanation.

Describe the forces both attractive and repulsive that occur as two atoms move closer together.

For the reaction c6h14(g) & longrightarrow; c6h6(g) + 4h2(g), δp(h2)/δt was found to be 2.5 x 10-2 atm/s, where δp(h2) is the change in pressure of hydrogen. determine δp(c6h14)/δt for this reaction at the same time.