5) (3 parts) calculate the average density of the following objects (assume they are all perfect spheres). use the steps detailed in the examples. show all your work (formulas used, numbers plugged in with proper units, and clearly indicate final answer! a) mass=6.0x1024kg, diameter=12000km (12,000,000 meters) b) mass=2.0x1030kg, diameter=1.4x106km c) what objects in our solar system are similar to the objects in part a and b in terms of size and density (see appendix tables)? which one has greater average density? 6) (2 parts) suppose you have a moon of mass of 4.8x1022kg, and a diameter of 3100km (3,100,000m). a) calculate the average density of this moon. b) considering that water ice has a density of around 1000kg/m3, and silicate rock is around 3000kg/m3, is the bulk of this satellite mostly ice or rock? show all !

5 a) Mass = 6.0 × 10²⁴ kg; d = 12 × 10⁶ m

The average density is 6600 kg/m³.

5 b) Mass = 2.0 × 10³⁰ kg; Diameter = 1.4 × 10⁶ km  

The average density is 1400 kg/m³.

5 c) Venus and the Sun are most like the objects in Parts a) and b). Venus has the greater density

6 a) Mass = 4.8 × 10²² km; Diameter = 3.1 × 10⁶ m

The average density of the moon is 3100 kg/m³.

6 b) The satellite appears to consist mostly of silicate rock.

first, consult an activity series chart to determine if al is more reactive than fe. it is, so it will replace the fe. now, one can continue with the problem.

next, make sure you have a correctly balanced equation.

3feo + 2al ==> 3fe + al2o3

now, determine which reactant (feo or al) is in limiting supply.

moles feo present = 125 g x 1 mole/71.8 g = 1.74 moles

moles al present = 25.0 g x 1 mole/26.98 g = 0.927 moles

since from the balanced equation, it take 3 mol feo for every 2 mol al, al will be limiting.

you can determine this simply by dividing moles of each by their coefficient in the balanced equation. for example: 1.74/3 = 0.58 and 0.927/2 = 0.464. al is less, so it is limiting.

finally, using the stoichiometry in the balanced eq. determine mass of fe that can be produced from 0.927 moles of al.

0.927 moles al x 3 moles fe/2 moles al x 55.8 g/mole = 77.6 g