Answer:
a)
⇒
⇒
b)
⇒
⇒
Explanation:
A)
Remember that positive number superscripts mean electrons lack and negative numbers mean electrons 'excess' (if we compare it with the neutral element). So, for the case of Fe2+ which is converted to Fe3+, we know that in Fe2+ there is a two electrons lack, while in Fe3+ there is a 3 electrons lack; it means that Fe2+ was converted to Fe3+ but releasing one electron:
⇒
The same analysis is applied to Br2; Br2 is a molecule which is said to have a zero superscript because it is an apolar covalent bond; and it is converted to Br-, which, according to what I wrote above, means that there is a one electron excess. So, Br2 must have received an electron in order to change to Br-; but Br2 can't change to Br- as simple as that because Br2 is a molecule, not an atom; it is a molecule that has two Br atoms, so, Br2 must give two Br- ions as products, but receiving one electron for each one:
⇒
b)
Applying the same, in Mg2+ there is a 2 electrons lack, and in Mg is not electron lack (its superscript is zero), so Mg must have released two electrons in order to change to Mg2+:
⇒
Cr3+ has a 3 electrons lack, and Cr2+ a two electrons one, so, Cr3+ must receive an electron to convert to Cr2+:
⇒
The amount of heat released by the sample has been 22.54 kJ. Thus, option C is correct.
The specific heat has been defined as the amount of heat required to raise the temperature of 1 gram of substance by 1 degree Celsius.
The specific heat has been expressed as:
<h3 /><h3>Computation for the heat absorbed</h3>
The iron and calorimeter are in side the closed system. Thus, the energy released by the sample, has been equivalent to the energy absorbed by the calorimeter.
The given mass of calorimeter has been, 
The specific heat of the calorimeter has been, 
The change in temperature of the calorimeter has been, 
Substituting the values for heat released:
The amount of heat released by the sample has been 22.54 kJ. Thus, option C is correct.
Learn more about specific heat, here:
brainly.com/question/2094845
Answer:
potential energy and kinetic energy
Answer:
c. To facilitate a reaction of one substrate to form two products without the use of water
Explanation:
A lyase is an enzyme that catalyzes - accelerates the chemical reaction - in which a substrate is broken into two molecules. The reaction does not involve hydrolysis or oxidation, so the water molecule is not included in the chemical reaction. Thus, the enzyme facilitates the reaction in which a molecule (substrate) is decomposed into two molecules with the elimination of chemical bonds.
The correct answer is that last one
