Answer:
CH₂
Explanation:
Given parameters:
Percentage composition:
Carbon = 40.1%
Hydrogen = 6.6%
Unknown:
Empirical formula of the compound = ?
Solution:
The empirical formula of a substance is its simplest formula.
Elements Carbon Hydrogen
Percentage
Composition 40.1 6.6
Molecular mass 12 1
Number of moles 40.1/12 6.6/1
3.342 6.6
Divide through by
the smallest 3.342/3.342 6.6/3.342
1 2
So the empirical formula of the compound is CH₂
Answer:
The molarity of a MnO4- solution
= 0.0342 M
Explanation:
Equation of reaction:
5Fe2 (aq) MnO4-(aq) 8H (aq) ---> 5Fe3 (aq) Mn2 (aq) 4H2O(l)
This is an example of redox titration.
Using titration formula:
CAVA/CBVA = NA/NB
where CA is the molarity of Fe2+ = (0.134 M)
CB is the molarity of MnO4- = (?????)
VA is the volume of Fe2+ = (30mL)
VB is the volume of MnO4- =(23.5mL)
NA is the numeric coefficient of Fe2+ in the equation of reaction = ( 5 )
NB is the numeric coefficient of MnO4- in the equation of reaction =(1)
Substituting the values into the formula;
0.134×30/CB×23.5 = 5/1
Therefore CB = 0.134×30/23.5×5
= 0.0342 M
There are 1,000 milligrams (mg) in one gram:
In 10 grams, there are 10 x 1,000 = 10,000 milligrams. This is a lethal dose of caffeine.
There are 4.05 mg/oz (milligrams/ounce) of caffeine in the soda.
In a 12 ounce can, there are 4.05 x 12 = 48.6 milligrams.
How many sodas would it take to kill you?
To find this, we divide the lethal dose amount (10,000 mg) by the amount of caffeine per can (48.6 mg).
10,000 ÷ 48.6 = 205.76.
Since 205 cans is not quite 10,000 mg, technically it would take 206 cans of soda to consume a lethal dose of caffeine.
Multiply it by the number of atoms of that element in the molecular formula.
