Answer:
0.7561 g.
Explanation:
- The hydrogen than can be prepared from Al according to the balanced equation:
<em>2Al + 6HCl → 2AlCl₃ + 3H₂,</em>
It is clear that 2.0 moles of Al react with 6.0 mole of HCl to produce 2.0 moles of AlCl₃ and 3.0 mole of H₂.
- Firstly, we need to calculate the no. of moles of (6.8 g) of Al:
no. of moles of Al = mass/atomic mass = (6.8 g)/(26.98 g/mol) = 0.252 mol.
<em>Using cross multiplication:</em>
2.0 mol of Al produce → 3.0 mol of H₂, from stichiometry.
0.252 mol of Al need to react → ??? mol of H₂.
∴ the no. of moles of H₂ that can be prepared from 6.80 g of aluminum = (3.0 mol)(0.252 mol)/(2.0 mol) = 0.3781 mol.
- Now, we can get the mass of H₂ that can be prepared from 6.80 g of aluminum:
mass of H₂ = (no. of moles)(molar mass) = (0.3781 mol)(2.0 g/mol) = 0.7561 g.
1 mol of any substance is made of 6.022 x 10²³ units.
When its 1 mol of a formula, its made of 6.022 x 10²³ formula units
Therefore if 6.022 x 10²³ formula units of CeI₃ make up 1 mol of CeI₃
Then 9.42 x 10²¹ formula units make up - 1/(6.022 x 10²³) x (9.42 x 10²¹) = 0.0156 mol of CeI₃
Therefore number of moles of CeI₃ - 0.0156 mol
- Increase in melting point;
- Trans- arrangements of side chains around double bonds that remains in the hydrogenated fat.
Explanation:
Vegetable oil contain a larger ratio of double bonds among all its carbon-carbon bonds than animal fat such as butter does. Unlike carbon-carbon single bonds, structures connected to carbon-carbon double bonds are unable to rotate around the bonding axis. As a result, molecules rich in double bonds aren't as malleable or stack as tightly as those with a smaller number of double bonds do. The spacy molecular configuration hinders the formation of intermolecular forces, such that in nature in comparison with animal fats, vegetable <em>oils</em> tend to demonstrate lower melting points.
Hydrogenating vegetable oils reduce the number of double bonds per molecule while attaching extra hydrogen atoms to carbon atoms that used to form double bonds. This process would increase the strength of intermolecular interaction, hence raising the melting point.
The hydrogenation process does not necessary convert <em>all</em> double bonds to single bonds; some double bonds remains in the molecule, preventing the rotation of structures on their sides. Double bonds in naturally-occuring fatty acids tend to be of the cis- configuration, with hydrogen atoms connected to the same side of the carbon-carbon double bond. The high temperature involved in the hydrogenation process (around 90 degrees Celsius) can trigger the flipping of atoms connected to these double bonds to produce trans- fatty acids with hydrogen atoms bonded to opposite sides of the double bond.
Saturated fats are when fatty acid contains carbon that are connected by a single bond. Unsaturated fats are when one or more carbons form a double bond with another carbon.
