A. Of a given element have different numbers of neutrons
Hrxn = Q reaction / mol of reaction
mol of reaction = M * V = 10 * 1 = 10 mmol = 0.01 mol
Q water = m * C * (Tf - Ti)
= (10 + 10) (4.184) (26-20) = 502.08 J
Q reaction = - Q water = -502.08 J
Hrxn = -502.08 / (0.01) = - 50208 J = - 50.21 kJ/mol
It could be Ne(Neon) or Ar(Argon) but the difference between both of them is that they are in different period Neon is in the 2 period and Argon is in 3 period
Answer
Density = 7.87g/cm^3
Explanation:
Density is the ratio of mass of the given object to the volume of the object, in this question iron is the given object, then we make use of atomic number of iron
Given:
Length= 287pm = 287*10^-10cm
Atomic mass of Fe= 56.0u
Z=2(for body centered cubic unit cell)
Avogadro number (N 0)=6.022× 10^23
Density= ZM/a^3 × N
Where
Z= body centered cubic unit cell
Then substitute
N= Avogadro's number
a=Length
Density = (2× 56)/(287*10^-10cm)^3 × (6.022 × 10^23)
Density = 7.87g/cm^3
