Answer:
The empirical formula = molecular formula = C13H18O2
Explanation:
in 100% compound we have 75.6 % Carbon ( Molar mass = 12g/mole), 8.80% hydrogen ( Molar mass = 1.01 g/mole) and 15.5% Oxygen (Molar mass = 16.01 g/mole).
Carbon: 75.6g / 12 = 6.29
Hydrogen: 8.80/ 1 = 8.80
Oxygen: 15.5/ 16 = 0.97
⇒0.97 is the smallest so we divide everything through by 0.97
C: 6.29 / 0.97 = 6.48 ≈ 6.5
H: 8.80 /0.97 = 9
O: 0.97 / 0.97 = 1
To get rid of decimals, we multiply by 2
C: 6.5 x 2 = 13
H: 9 x 2 = 18
O: 1 x 2 = 2
The empirical formula = C13H18O2
13x 12g/mol + 18x1g/mol + 2x 16g/mol = 156 + 18 + 32 = 206g/mol which is the molar mass of ibuprofen
The empirical formula = molecular formula = C13H18O2
Answer:

Explanation:
Hello,
In this case, due to the volume displacement caused the by the object's submersion, it's volume is:

In such a way, considering the mathematical definition of density, it turns out:

Rounding to the nearest tenth we finally obtain:

Regards.
Answer:
2023.04 g
Explanation:
Magnetite reacts with hydrogen to produce Iron metal and steam. Steam instead of water is produced as the reaction occurs at temperatures above the boiling point of water.
Fe₃O₄ + 4 H₂ → 3 Fe +4 H₂O
From the equation, 1 mole of Fe₃O₄ reacts with 4 moles of H₂.
69.76 grams of H₂ has the following number of moles.
Number of moles= mass/RAM
=69.76/2
=34.88 moles.
The reaction ratio of Fe₃O₄ to H₂ is 1:4
Thus number of moles of magnetite= (1×34.88)/4
=8.72 moles.
Mass= moles × molecular weight
=8.72 moles × (56×3+16×4)
=2023.04 grams
Answer:
3.14 grams of ammonium thiocyanate must be used to react completely with 6.5 g barium hydroxide octahydrate.
Explanation:

The balance chemical equation is :

Mass of barium hydroxide octahydrate = 6.5 g
Moles of barium hydroxide octahydrate = 
According to reaction, 2 moles of ammonium thiocyanate reacts with1 mole of barium hydroxide octahydrate. The 0.020635 moles of barium hydroxide octahydrate will react with:

Mass of 0.04127 moles of ammonium thiocyanate;

3.14 grams of ammonium thiocyanate must be used to react completely with 6.5 g barium hydroxide octahydrate
Answer:
isotope 2
Explanation:
it has the highest percentage abundance