Some hypothetical alloy is composed of 25 wt% of metal A and 75 wt% of metal B. If the densities of metals A and B are 6.17 and 8.00 g/cm3 , respectively, and their respective atomic weights are 171.3 and 162.0 g/mol, determine whether the crystal structure for this alloy is simple cubic, facecentered cubic, or body-centered cubic. Assume a unit cell edge length of 0.332 nm

Simple cubic

Explanation:

The density of metal A (ρa) = 6.17 g/cm³, The density of metal B (ρb) = 8 g/cm³, The atomic weight of metal A (Aa) = 171.3 g/mol, The atomic weight of metal B (Ab) = 162 g/mol, the unit cell edge length (a) = 0.332 nm, concentration of metal A (Ca) = 25%, concentration of metal B (Cb) = 75%

The average density is given by:

n≅1

Since n≅1, the crystal structure for this alloy is simple cubic

answer: enthalpy

explanation:

for a exothermic reaction, the energy is released i.e. the energy of the products is lower than the energy of the reactants.

= enthaply

= energy of products

= energy of reactants

as , thus comes out to be negative. negative value of enthalpy shows that the reaction is exothermic.

  the   balanced   equation   for   reaction of   ca metal   with   o2 to   produce   cao   is as below

2 ca+ o2→ 2 cao2

  explanation

the reaction is   balanced     since the   number of atoms   in reactant side is   equal to   number of atoms   in   product side.   for   example   they   are 2   atom of   ca in   reactant   side   and   2   atoms of ca   in   the product side.

  the   process   is a   meet the   requirement   of   redox   reaction because :     calcium   is   oxidized   from   oxidation state 0   to 2+   while   oxygen   is reduced from   oxidation   state   0   to 2-