An unknown element X can form a compound with the formula XBr3. In which group on the Periodic Table would element X be found?

(1) 1 (3) 13

(2) 2 (4) 14

The number of protons in the nucleus of the atom

Calculate the number of moles in 9g of water

Gaseous neon has a density of 0.900 g/L at standard conditions. How many neon atoms are in 1.00 L of neon gas at standard conditions?

If you start with 13.4g of c3h8 and 4.35g of o2 determine the limiting reagent

What process uses analysis of the decay of atomic particles to determine exact age? Radioactive dating Law of superposition Relative dating Geologic time

A sample of hydrogen gas is mixed with water vapor. The mixture has a total pressure of 755 torr and the water vapor has a partial pressure of 24 torr. What amount (in moles) of hydrogen gas is contained in 1.55 L of this mixture at 298 K?

Both equation I and II are balanced, but equation II is the correct way to write the balanced equation. Why do you think this is? (Hint: Think fractions.) I) 2 SnO2 + 4 H2 → 2 Sn + 4 H2O II) SnO2 + 2 H2 → Sn + 2 H2O

If some of the salt remains adhered to the weighing paper (and therefore is not transferred to the calorimeter), will the enthalpy of solution for the salt be reported too high or too low?

In one process, 5.95 kg of caf2 is treated with an excess of h2so4 and yields 2.45 kg of hf. calculate the percent yield of hf.

What are 3 ways to increase the solubility of a solid substance in a solid?