[Tom]

My son and I need assistance with these T or F questions, can we get some assistance. Thanks, Tom and James


11.   The most stable oxidation state of Ni, Cu, and Zn in aqueous solution is +2.
12.   The addition of a common anion to a solution of a weak acid will cause the percent ionization of that acid to decrease.
13.   A chemical change occurs when the composition of the substance is altered.
14.   If the concentrations of the products are decreased for a reaction that is in equilibrium, the reaction will shift right until equilibrium is restored.
15.   The emission of an alpha particle by a parent nuclide produces a daughter nuclide with two fewer neutrons.
16.   Bonding between halogen atoms is best described as an overlap of s orbitals on the halogen atoms.
17.   If a reaction follows Arrheius' theory, a plot of the logarithm of the rate constant, 1n(k), vs. the absolute temperature, T, is a straight line.
18.   A mole is a quantity of matter that can be conveniently measured on a laboratory balance.
19.   The Group III cations form sulfides that are more soluble than the Group II cations.      
20.   Metallic solids have excellent electrical and thermal conductivity because the valance electrons are delocalized throughout the solid.

[Donaldson Tan]

First, begin by clicking the URL below first:
http://www.chemicalforums.com/index.php?board=2;action=display;threadid=58

11. Check the electrode potential values for the cations of these metals with oxidation +2

12. Le Chaterlier's Princple states that the system at equilibirum will act in a way to counter the stress acting on the system. Eg, you increase the amount of a certain species, the system will respond by reducing the amount of that species.

13. a chemical reaction is said to occur when a new substance is formed.

14. refer to (12)

15. An alpha particle is a Helium nucleus.

16. Do you think there are s orbitals available for bonding in the valence shell?

17. Why dont you try applying Loge on Arrhenius Equation?

18. I am sure any chemistry dictionary will give you your answer.

19. Generally, Group (III) Sulphides have more exothermic lattice energy than that of Group (II).

20. http://www.chs.edu.sg/~limth/lessons/2002/ASB/metallic_bonding.htm
   

[jdurg]

Well, the molar mass of carbon is ~12 g/mol, and that of hydrogen is about 1 g/mol.  So with that information, I think you are a bit off on your calculations.  All you'll need to do is set up a simple algebraic expression with x standing in for number of carbon atoms and y representing the number of hydrogen atoms.  Since they already give you the weight percentages and you know one mole is 90 grams, it should be pretty simple to figure it out.