What chemical reaction does this equation represent?
2kcl + pb(no3)2 = 2kno3 + pbcl2

a: two molecules of potassium nitrate and one molecule of lead chloride react to form one molecule of lead nitrate and two molecules of potassium chloride.

b: one molecule of potassium nitrate and one molecule of lead chloride react to form one molecule of lead nitrate and one molecule of potassium chloride.

c: two molecules of potassium chloride react with two molecules of lead nitrate to form one molecule of potassium nitrate and two molecules of lead chloride.

d: two molecules of potassium chloride react with one molecule of lead nitrate to form two molecules of potassium nitrate and one molecule of lead chloride.

Answer is: D: Two molecules of potassium chloride react with one molecule of lead nitrate to form two molecules of potassium nitrate and one molecule of lead chloride.

Balanced chemical reaction: 2KCl + Pb(NO₃)₂ → 2KNO₃ + PbCl₂.

According to principle of mass conservation, number of atoms must be equal on both side of balanced chemical reaction.

KCl - potassium chloride.

Pb(NO₃)₂ - lead nitrate.

KNO₃ - potassium nitrate.

PbCl₂ - lead chloride.

the answer is 0.42 is that is an option. this question provides no info

answer: semi-infinite solid initially at a uniform temperature of 400 ◦c is cooled at its surface by convection. the cooling fluid at a constant temperature of 200 ◦c has a convective coefficient (ha) of 250 w/m2.k. the physical properties of the solid: k = 20 w/m.k and α = 4 * 10-5  m2/s. using δx = 0.04 m and δt = 10 s. write the finite difference equations describing the transient heat transfer of the first five δx and the temperature profile after 30 s.