Chemical Quantities "Molar Mass - 2 step" - Wksh #3 Directions: Use dimensional analysis to perform the following calculations. Show all work, (K and U) include your units and box your final answers. 1. How many molecules are in 13.5 g of sulfur dioxide, SO2? 2. What is the mass of 2.23 x 1023 atoms of sulfur? 3. How many formula units of silver fluoride, AgF, are equal to 42.15 g of this substance? 4. What is the mass of 8.83 x 1023 formula units of Iron (III) oxide, Fe2O3?

4d^55s^1 ( third choice)

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.