Answer:
3.67 moles of N
Explanation:
The epinephrine's chemical formula is: C₉H₁₃O₃N
We were told that a chemist found that in a mesaure of epinephrine, he found 33 moles of C
We must know that 9 moles of C are in 1 mol of C₉H₁₃O₃N so, let's make a rule of three:
If 9 moles of C are found in 1 mol of C₉H₁₃O₃N
Therefore 33 moles of C must be found in (33 .1) / 9 = 3.67 moles of C₉H₁₃O₃N
There is a second rule of three, then.
In 1 mol of C₉H₁₃O₃N we have 1 mol of N
Then, 3.67 moles C₉H₁₃O₃N must have (3.67 . 1) / 1 = 3.67 moles of N
Remember 1 mol of C₉H₁₃O₃N has 9 moles of C, 13 moles of H, 3 moles of O and 1 mol of N
Answer:
6.05g
Explanation:
The reaction is given as;
Ethane + oxygen --> Carbon dioxide + water
2C2H6 + 7O2 --> 4CO2 + 6H2O
From the reaction above;
2 mol of ethane reacts with 7 mol of oxygen.
To proceed, we have to obtain the limiting reagent,
2,71g of ethane;
Number of moles = Mass / molar mass = 2.71 / 30 = 0.0903 mol
3.8g of oxygen;
Number of moles = Mass / molar mass = 3.8 / 16 = 0.2375 mol
If 0.0903 moles of ethane was used, it would require;
2 = 7
0.0903 = x
x = 0.31605 mol of oxygen needed
This means that oxygen is our limiting reagent.
From the reaction,
7 mol of oxygen yields 4 mol of carbon dioxide
0.2375 yields x?
7 = 4
0.2375 = x
x = 0.1357
Mass = Number of moles * Molar mass = 0.1357 * 44 = 6.05g
Answer is: intramolecular attractions are stronger.
Intramolecular attractions are the forces between atoms in molecule.
There are several types of intramolecular forces: covalent bonds, ionic bonds.
Intermolecular forces are the forces between molecules. The stronger are intermolecular forces, the higher is boiling point of compound, because more energy is needed to break interaction between molecules.
There are several types of intermolecular forces: hydrogen bonding, ion-induced dipole forces, ion-dipole forces andvan der Waals forces.
Hydrogen bonds are approximately 5% of the bond strength of covalent C-C or C-H bonds.
Hydrogen bonds strength in water is approximately 20 kJ/mol, strenght of carbon-carbon bond is approximately 350 kJ/mol and strengh of carbon-hydrogen bond is approximately 340 kJ/mol.
20 kJ/350 kJ = 0.057 = 5.7 %.
The moles of Ba(OH)2 that is required to react with 117 HBr is calculated as below
find the moles of HBr used
mass/ molar mass = 117 g/ 80.9 g/mol = 1.446 moles
write the reacting equation
Ba(OH)2 + 2 HBr = BaBr2 + 2 H2O
by use of mole ratio of Ba(OH)2 : HBr which is 1:2 the moles of Ba(OH)2 is therefore
= 1.446 moles x1/2 = 0.723 moles of Ba(OH)2
