2al + 6hcl → 2alcl3 + 3h2 if the chemical reaction produces 129 grams of alcl3, how many grams of h2 are also produced? a. 1.22 b. 2.92 c. 3.02 d. 3.65

B. 2.92

Explanation:

n = mass / molar mass,

∴ n of AlCl₃ = (129.0 g) / (133.34 g/mol) = 0.967 mol.

Using cross multiplication:

2.0 moles of AlCl₃ produced with → 3.0 moles of H₂, from the stichiometry.

0.967 moles of AlCl₃ produced with → ??? moles of H₂.

∴ the number of moles of H₂ = (0.967)(3.0) / (2.0) = 1.45 mol.

∴ The grams of H₂ = n x molar mass = (1.45 mol)(2.01588 g/mol) = 2.92 g.

0.88m hope i am correct : )

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.