posted by Sara .
A couple questions here:
1. How do you expect nitriding to change the properties of iron?
a) Nitriding makes iron stronger.
b) Nitriding makes iron weaker.
c) Nitriding makes iron more electrically conductive.
d) Nitriding makes iron less electrically conductive.
2. Calculate the relative number of atoms of each element contained in each of the following alloys. (Assume the amounts per 100 g of the alloy.)
(a) Wood's metal, which is a low-melting-point alloy used to trigger automatic sprinkler systems and is 12.5% tin, 12.5% cadmium, and 24% lead by mass in bismuth
(b) a stainless steel that is 13% chromium in iron
I have some thoughts on #1 but I can't confirm them so I'll leave that one alone.
#2 a and #2 b are the same kind of problem. Here is how you do #2a.
Take a 100 g sample.
12.5 g Sn
12.5 g Cd
24 g Pb
100 - (g Sn - g Cd - g Pb) = g Bi.
Then mols = grams/molar mass
Using mols of each, determine relative mols (in whole numbers). If you get stuck post your work and I can help you through it. All this is is finding the empirical formula for woods metal.