Scientists use a Graduated Cylinder
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:
vHe / vNe = 2.24
Explanation:
To obtain the velocity of an ideal gas you must use the formula:
v = √3RT / √M
Where R is gas constant (8.314 kgm²/s²molK); T is temperature and M is molar mass of the gas (4x10⁻³kg/mol for helium and 20,18x10⁻³ kg/mol for neon). Thus:
vHe = √3×8.314 kgm²/s²molK×T / √4x10⁻³kg/mol
vNe = √3×8.314 kgm²/s²molK×T / √20.18x10⁻³kg/mol
The ratio is:
vHe / vNe = √3×8.314 kgm²/s²molK×T / √4x10⁻³kg/mol / √3×8.314 kgm²/s²molK×T / √20.18x10⁻³kg/mol
vHe / vNe = √20.18x10⁻³kg/mol / √4x10⁻³kg/mol
<em>vHe / vNe = 2.24</em>
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I hope it helps!
