Given Calcium has electronegativity of 1.0. Fluorine has electronegativity of 4.0. 1) Which kind of bond will they likely to form: ionic or covalent, and provide evidence to support your claim. 2) If it forms ionic bond, which one gives up its electrons and why?
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4 points
1) Calcium and Fluorine will likely form an ionic bond. This is because the electronegativity difference between the two elements is 3.0 (4.0 - 1.0), which is greater than 1.7. An electronegativity difference greater than 1.7 indicates a highly polar bond, which typically results in the formation of an ionic bond.
2) In an ionic bond between Calcium and Fluorine, Calcium will give up its electrons to Fluorine. This is because Fluorine has a higher electronegativity than Calcium, meaning it has a greater ability to attract electrons. As a result, Calcium will lose its outermost electrons to Fluorine, forming a positively charged Calcium ion and a negatively charged Fluorine ion.
What is the total change in bond energy for the reaction below? Is the reaction exothermic or endothermic?
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4 points
Br2(g) + 3F2(g) -> 2BrF3(g)
bond bond energy (kj/ml)
Br-Br 192
F-F 158
Br-F 197
To calculate the total change in bond energy for the reaction, we first need to determine the bonds broken and bonds formed in the reaction.
Bonds broken:
1 Br-Br bond (192 kJ/mol)
3 F-F bonds (3 * 158 kJ/mol)
Bonds formed:
6 Br-F bonds (6 * 197 kJ/mol)
Now, let's calculate the total change in bond energy:
Total bond energy broken = 192 kJ/mol + 3 * 158 kJ/mol = 666 kJ/mol
Total bond energy formed = 6 * 197 kJ/mol = 1182 kJ/mol
Total change in bond energy = Total bond energy formed - Total bond energy broken
Total change in bond energy = 1182 kJ/mol - 666 kJ/mol = 516 kJ/mol
Since the total change in bond energy is positive (516 kJ/mol), the reaction is endothermic. This means that energy is absorbed during the reaction.