Organic compounds contain carbon
Delta H of solution = -Lattice Energy + Hydration
<span>Delta H of solution=- (-730)+(-793) </span>
<span>Delta H of solution= -63kJ/mol </span>
<span>Now we find moles of LiI: </span>
<span>10gLiI/133.85g=.075moles </span>
<span>multiply moles to the delta H of solution to cross cancel moles. .75moles x -64kJ/mol =4.7</span>
The charge of Br changed from –1 to 0, therefore it is the
element which is oxidized. Since it is oxidized then Br is also the reducing
agent.
The charge of Mn changed from +4 to +2 therefore it is the
element which is reduced. Since Mn is reduced, then MnO2 is the oxidizing
agent.
The half –reactions are:
Br: 2Br --> Br2 + 2e-
Mn: MnO2 --> Mn2+
First balance oxygen by adding H2O:
MnO2 --> Mn2+ + 2H2O
Then balance hydrogen by adding H+ ions:
4H+ + MnO2 --> Mn2 + 2H2O
Then the appropriate electrons:
4e- + 4H+ + MnO2 --> Mn2 + 2H2O
Multiply the half-reaction of Br by 2 because the half-reaction
of Mn has 4 electrons.
4Br --> 2Br2 + 4e-
Combine the two half reactions and cancel common factors:
4Br- + 4H+ + MnO2 --> 2Br2 + Mn2 + 2H2O
c. 1.5 moles of Cu will contain a total of 9.0 * 10 ^ 23 atoms.
Explanation:
To convert moles into atoms, the molar amount and number of atom is multiplied by Avagadro's number.
Avagadro's number is 6.022×
So applying the formula in the given sample:
A) 0.5×6.022×
3.01× atoms.
B) 0.75 mole of H20
O.75×6.022×
= 4.5166× atoms.
C) 1.5 moles of Cu
1.5×6.022×
= 9.033×
D). 1.5 moles of H2
1.5 × 2 × 6.022 ×
= 18.066 × atoms because H2 is 2 moles of hydrogen.
Atom is the smallest entity of matter having property of the element to which it is a part.
