Friday
December 13, 2013

# Posts by Chemistry

Total # Posts: 180

chem
A molecular compound is composed of 58.8% Xe, 7.2% O, and 34.0% F, by mass. If the molecular weight is 223 g/mol, what is the molecular formula? Draw the correct Lewis structure. Predict the molecular geometry using the VSEPR model.

chem
A gaseous compound has the following composition by mass: C, 25.0%; H, 2.1%; F, 39.6%; O, 33.3%. Its molecular weight is 48 g/mol

chemistry
An ionic compound has the following composition (by mass): Mg, 10.9%; Cl, 31.8%; O, 57.3%. What is the formula and name of this compound?

chemistry
Consider the hypothetical elements X and Y. Suppose the enthalpy of formation for the compound XY is ƒ{336 kJ/mol, the bond energy for X2 is 414 kJ/mol, and the bond energy for Y2 is 159 kJ/mol. Estimate the XY bond energy in units of kJ/mol.

chemistry
What is the lattice energy of NaBr? heat of formation of NaBr = -362 kJ/mol heat of sublimation for Na = 107.30 kJ/mol ionization energy for Na = 496 kJ/mol bond dissociation energy for Br2 = 190 kJ/mol electron affinity of Br = -325 kJ/mol heat of vaporization for Br2 = 30.90...

chemistry
it worked now, thank you!

chemistry
9904.7 is the answer but I already tried that and its not working

chemistry
Given the reaction 3C(s) + 4H2(g) + 5O2(g) ---> 3CO2(g) + 4H2O(l) ÄH= -2323.7 kJ How much heat would be released when 34.1 g of H2 react?

Kelsie
name the element wsith the atomic number z= 15 and the atomic mass number 31. How many electrons does the neutral of this lement have? How many neutrons does the neutral atoms of this element have? I know the element with the atomic number of 15 and atomic mass of 31 is phosph...

tere
what did i do wrong? i need to find lowest vapor pressure. a 0.13 m FeCl3 b 0.50 m sucrose c 0.24 m NaNO3 d 0.15 m Na2PO4 so i solved. a 4 x 0.13 = 0.52 b 1 x 0.50 = 0.50 c 5 x 0.24 = 1.2 d 7 x 0.15 = 1.05 i chose C but the answer is A. did i do something wrong?

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