Determine the standard enthalpy change in the following reaction. ΔfH∘ (Mg (OH)2 (s) ) = −924.5 kJ/mol
ΔfH∘ (H2O (l) ) = −285.8 kJ/mol
ΔfH∘ (NH3 (g) )= −46.11 kJ/mol
Mg(OH)2 (s) + 2NH+4 (aq) → Mg2+ (aq) + 2H2O (l) +2NH3 (g)

ΔrH∘= ?

it forms an anion that has a larger radius. anions have a negative charge and are larger than the original atom.

(b) which contains higher levels of vitamin b, oranges or spinach?

explanation:

you can eliminate a, c, and d because they are questions based on opinions.

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.