What is the composition, in atom percent, of an alloy that consists of 4.5 wt% pb and 95.5 wt% sn? the atomic weights for pb and sn are 207.19 g/mol and 118.71 g/mol, respectively.(a) 2.6 at% pb and 97.4 at% sn(b) 7.6 at% pb and 92.4 at% sn(c)97.4 at% pb and 2.6 at% sn(d) 92.4 at% pb and 7.6 at% sn

The correct answer is Option A.

Explanation:

We are given:

4.5 wt % of Pb means that 4.5 grams of lead is present in 100 g of alloy.

95.5 wt % of Sn means that 95.5 grams of tin is present in 100 g of alloy.

To calculate the atom percent of any compound in a mixture, we use the equation:

where,

= Avogadro's number

Moles of a compound is given by the formula:

Given mass of lead = 4.5 g

Molar mass of lead = 207.19 g/mol

Given mass of tin = 95.5 g

Molar mass of tin = 118.71 g/mol

Hence, the correct answer is Option A.

a). in this case, dh> 0 and sd> 0. if t becomes larger, the term "-tds" will become more negative. at some point, it is possible that -dts will be more negative than the dh is positive, and the reaction will become spontaneous. this is probably the correct answer, but you should look at all of the other possibilities and make sure of that.