2. Certain compounds called aerogels form rigid, lightweight foams that can

support a mass many times greater than their own. If a sample of an aerogel

has a volume of 8.73 cm and a density of 0.250 g/cm. what is its mass?

Which set of quantum numbers is not permitted by the rules of quantum mechanics?

Are dienes, saturated or unsaturated molecules?

Which of the following laboratory procedures best illustrates the law of conservation of mass? Calculating the number of atoms in 11 g of Na Using 250 g of impure Cu to obtain 200 g of pure Cu Heating 32 g of S and 56 g of Fe to produce 88 g of FeS

The process of passing electricity through water to chemically separate it into hydrogen and oxygen is called

Acetylene gas (C2H2) used in welding, pro - duces an extremely hot flame when it burns in pure oxygen according to the reaction 2 C2H2 (g) + 5 O2 (g) - → 4 CO2 (g) + 2 H2O (g). How much CO2 is produced when 20000 g of C2H2 burns completely?

Identify the spectator ions in the following complete ionic equation. 2k (aq) s2 - (aq) pb2 (aq) 2no-3 (aq) →pbs (s) 2k (aq) 2no-3 (aq) express your answers as ions separated by a comma.

4. A bird left its post and flew in a triangular path. It flew 21 yards south, 72 yards east and 75 yards diagonally to end back at the post. Is it a right triangle?

Condension occurs in the inside of your windows in Winters, why?

How can you use Hess's law to determine a reaction's enthalpy?

7. How much energy in KJ is released when 15.0 g of steam at 100.0 degrees Celsius is condensed and then frozen to ice at 0.0 degrees Celsius?