84 divided by 2 = 42.
2 goes into 8 four times, so there would be your 4.
Then 2 goes into 2 one time, and there would be your 2.
You check your answer by multiplying 42 by 2, which would give you, 84.
A phospholipid has a charged head and an uncharged tail.
Explanation:
i guess it's through thousands of research and experiments they conducted
To get the empirical formula, we need to know the ratio of the moles of both lead and sulfur.
First, lets get the mass of each:
mass of lead = mass of evaporating dish and lead - mass of empty dish
= <span>26.927 - 25.000 = 1.927 gm of lead (Pb)
mass of sulfur = mass of dish and lead sulfide - mass of dish and lead
= </span><span>27.485 - 26.927 = 0.558 gm of sulfur (S)
The next step is to get the number of moles in 1.927 gm of Pb and in 0.558 gm of S:
From the periodic table:
molar mass of lead = </span>207.2 gm<span>
molar mass of sulfur = 32 gm
number of moles = mass / molar mass
number of moles of Pb = 1.927 / 207.2 = </span>0.0093 moles<span>
number of moles of S = 0.558 / 32 = </span><span>0.0174 moles
The third step is to get the ratio between the moles by dividing the number of moles of each by the smaller of the two:
1 mole of Pb (</span>0.0093 / 0.0093) reacts with 0.0174 / 0.0093 = 1.99 (approximately 2 moles) of sulfur.
Final step is to write the empirical formula based on the ratio:
Lead sulfide compound is written as : PbS2
