When we write a formula of a compound in its simplest form, it is empirical formula.
Given the molecular formula is = C₁₈H₃₆
Now we can relate both empirical and molecular formula as;
Molecular formula = n x empirical formula
C₁₈H₃₆ = 18 x CH₂
So the empirical formula of C₁₈H₃₆ is CH₂
<span> Mg(OH)2(s) + 2HCl(aq) yield MgCl2(aq) + 2H2O(l)
grams HCl required = (50.6 grams Mg(OH)2) * (1 mol Mg(OH)2 / 58.3197 grams Mg(OH)2) * (2 mol HCl / 1 mol Mg(OH)2) * (36.453 grams HCl / 1 mol HCl) = 63.26 grams HCl required
Since there are only 45.0 grams HCl, then HCl is the limiting reactant.
theoretical yield MgCl2 = (45.0 grams HCl) * (1 mol HCl / 36.453 grams HCl) * (1 mol MgCl2 / 2 mol HCl) * (95.211 grams MgCl2 / 1 mol MgCl2) = 58.6 grams MgCl2 </span>
The density of metal = 4.5 g/ml, and the metal = Titanium
<h3>Further explanation </h3>
Density is a quantity derived from the mass and volume
Density is the ratio of mass per unit volume
Density formula:

ρ = density
m = mass
v = volume
mass of metal=27 g
volume = 6 ml
The density :

The metal with a density of 4.5 g/ml is Titanium
The answer is C. Because planet A experiences a stronger gravitational field, it will have a larger acceleration due to gravity, and therefor orbit faster than planet B