Molar mass ethanol:
C2H5OH = 12 x 2+ 1 x 5 + 16 + 1 = 46.0 g/mol
volume = 545 mL in liters: 545 / 1000 => 0.545 L
number of moles:
29.0 / 46.0 => 0.6304 moles
M = n / V
M = 0.6304 / 0.545
M = 1.156 mol/L
hope this helps!
The last row going across
The way you calculate the empirical formula is to firstly assume 100g. To find each elements moles you take each elements percentage listed, times it by one mole and divide it by its atomic mass. (ex: moles of K =55.3g x 1 mole/39.1g, therefore there is 1.41432225 moles of Potassium) Once you’ve completed this for every element you list each elements symbol beside it’s number of moles and divide by the smallest number because it can only go into its self once. After you’ve done this, you’ve found your empirical formula, which is the simplest whole number ratio of atoms in a compound. I’ve added an example of a empirical question I completed last semester :)
Answer: -
The acceleration due to gravity at height r = a = GM/r²
Rearranging
r² = GM /a
= (6.674 x 10⁻¹¹ x 5.972 x 10²⁴ ) / 5
r = 8.917 x 10⁶ m
r = 8917 Km
Now Radius of earth = 6371 Km
So height = 8917 - 6371 = 2546 Km
Answer: Edge length of the unit cell = 628pm
Explanation: For a body centred cubic structured system, the relationship between the edge length of the unit cell and radius of the atoms in the structure is
Edge length of Unit cell (a) = (4R)/(√3)
R = 272pm = (272 × (10^-12))m = (2.72 × (10^-10))m
a = (4 × (2.72 × (10^-10)))/(√3)
a = (6.28157 × (10^-10))m = 628pm