Elements X and Y form the compound XY3. When these elements react it is found that 1.00 g of X combines with 1.84 g of Y. When X combines with oxygen, it forms the compound
X2O5 in which 1.00 g of X combines with 1.29 g of oxygen. Find the molar mass of XY3.
help me

2. Calculate how many mL of 0.100 M hydrochloric acid must be added to a 50.0 mL of
0.400 M hydrochloric acid to produce a final solution having a molarity of 0.250 M.

3. Explain the following observations using the appropriate intermolecular forces operating in them.
(a) H2O boils at a much higher temperature compared to H2S.
(b) NaCl dissolves in water.
(c) CH3-O-H is soluble in water whereas CCl4 is not.
(c) AlCl3 is a solid while PCl3 is a liquid
(d) The boiling and melting points of halogens increases from F2 to I2.

(5 Oxygen) * (16 gm) * (1 / 1.29) * (1/2) = Mass of X

(Mass of X) *(1.84/3) = Mass of Y

Mass of X + (3 * Mass of Y)



((.05L * .4 mol/L) + (V * .1 mol/L)) / (.05L + V) = .25 mol/L


(a) H2O is hydrogen bonding which is stronger than london bonding forces

(b) NaCl is an ionic compound with Na having +1 and Cl having -1. Water has a slightly positively charged end near the H and a slightly negative charged end near O. When NaCl is placed in water the positively charged Na like to congregate near the negatively charged O and the negatively charged Cl like to congregate near the positively charged H.

(c) CH3-O-H is polar and CCl4 is not. Polar solutes tend to dissolve in polar solvents.

(d) Despite having covalent bonding, AlCl3 is ionic in nature due to Al being a metal while PCl3 is not.

(e) An I2 molecule is larger than an F2 molecule, so the I2 molecule will have more electrons floating around setting up dipole interactions leading to greater van der waals forces. Greater van der waals forces means that you are going to have to apply more heat to convert to a liquid or gas.

This post was edited by RzChaos on May 18 2015 04:54pm