Decompostion reaction have the general chemical reaction of: AB = A + B while synthesis reactions are of the general equation A + B = AB. These reaction can be the reverse of each other because ones building a compound (synthesis) and ones breaking down a compound (decomposition). For example, when reacting carbon and oxygen for a synthesis reaction we have: C + O2 = CO2 and for a decomposition reaction we have: CO2 = C + O2. Thus, these two reactions are the reverse of each other.
We can calculate how long the decay by using the half-life equation. It is expressed as:
A = Ao e^-kt
<span>where A is the amount left at t years, Ao is the initial concentration, and k is a constant.
</span><span>From the half-life data, we can calculate for k.
</span>
1/2(Ao) = Ao e^-k(30)
<span>k = 0.023
</span>
0.04Ao = Ao e^0.023(t)
<span>t = 140 sec</span>
<span>Avogadro's law applies at STP where P is 1 atm and T is 273K. From Avogadro's law; 1 mole of gas takes up 22.4 L of volume at STP. I. e 1 moles = 22.4 L. Hence 1.2 moles of water vapor will take up. 1.2 * 22.4 = 26.88L. Or using ideal ga s eqn PV = NRT. We have P = 1 atm. N = 1.2 moles. R = 0.0821 L and T =273 K. So V = NRT/P.Then we have 1.2 * 0.0821 * 273 = 26.88L.</span>
I can try.
Whats the question
Answer:
B. Electrons are gained, so the oxidation number decreases.
Explanation:
Reduction is the <em>gain of electrons</em>.
Oxidation number is the charge that an atom <em>appears</em> to have when we count its electrons in a specific way.
Electrons have a negative charge so, if an atom gains electrons, its charge (oxidation number) becomes more negative. The oxidation number decreases.
If electrons are given off, the atom is being oxidized. Loss of electrons is <em>oxidation</em>.
