20. An atom has a mass of 50 and 20 protons. How many

neutrons does it have?

Answer:

What is the mol:mol ratio of nonane to carbon dioxide

The chemical formula for potassium bromide is KBr. A chemist determined by measurements that 0.0250 moles of potassium bromide participate in a chemical reaction. Calculate the mass of potassium bromide that participates.

How do the scientists use observations to make predictions?

An antifreeze solution is made by mixing ethylene glycol (ρ = 1116 kg/m3) with water. suppose the specific gravity of such a solution is 1.05.

In part A of the experiment you will need to make a 4.80 x 10-4 M KSCN solution starting with a 2.00 x 10-3M KSCN solution. You will be making up the solution in a 25.00 mL volumetric flask and using 0.5 M HNO3 as the diluent. What volume of 2.

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?

Consider the reaction: 8H2S (g) + 4O2 (g) →8H2O (g) + S8 (g). Δ[H2S]/Δt = - 0.033M/s. Find Δ[O2]/Δt. Δ[H2O]/Δt. Δ[S8]/Δt. Find the rate of the reaction.