Its water as common name and hydrogen monoxide as molecular name
Answer:
5.0 x 10⁹ years.
Explanation:
- It is known that the decay of a radioactive isotope isotope obeys first order kinetics.
- Half-life time is the time needed for the reactants to be in its half concentration.
- If reactant has initial concentration [A₀], after half-life time its concentration will be ([A₀]/2).
- Also, it is clear that in first order decay the half-life time is independent of the initial concentration.
- The half-life of K-40 = 1.251 × 10⁹ years.
- For, first order reactions:
<em>k = ln(2)/(t1/2) = 0.693/(t1/2).</em>
Where, k is the rate constant of the reaction.
t1/2 is the half-life of the reaction.
∴ k =0.693/(t1/2) = 0.693/(1.251 × 10⁹ years) = 5.54 x 10⁻¹⁰ year⁻¹.
- Also, we have the integral law of first order reaction:
<em>kt = ln([A₀]/[A]),</em>
where, k is the rate constant of the reaction (k = 5.54 x 10⁻¹⁰ year⁻¹).
t is the time of the reaction (t = ??? year).
[A₀] is the initial concentration of (K-40) ([A₀] = 100%).
[A] is the remaining concentration of (K-40) ([A] = 6.25%).
∴ (5.54 x 10⁻¹⁰ year⁻¹)(t) = ln((100%)/( 6.25%))
∴ (5.54 x 10⁻¹⁰ year⁻¹)(t) = 2.77.
∴ t = 2.77/(5.54 x 10⁻¹⁰ year⁻¹) = 5.0 x 10⁹ years.
The cell notation for the voltaic cell that incorporates the redox reaction Mg(s) + Sn²⁺(aq) → Mg²⁺(aq) + Sn(s) is Mg(s)|Mg²⁺(aq)║Sn²⁺(aq)|Sn(s).
The cell notation for a voltaic cell is the following:
anode ║ cathode
The anode is where the oxidation reaction takes place and the cathode is where the reduction happens.
The given reaction is:
Mg(s) + Sn²⁺(aq) → Mg²⁺(aq) + Sn(s)
We can see that <u>magnesium </u>is <u>oxidizing</u> (it is losing electrons) and that <u>tin </u>is <u>reducing</u> (it is gaining electrons).
These two processes can be represented in the following half-reactions:
Oxidation: Mg(s) → Mg²⁺(aq)
Reduction: Sn²⁺(aq) → Sn(s)
Which in <u>cell notation</u> is:
Anode: Mg(s)|Mg²⁺(aq)
Cathode: Sn²⁺(aq)|Sn(s)
Hence, the <u>notation</u> for the <u>voltaic cell</u> is:
Mg(s)|Mg²⁺(aq)║Sn²⁺(aq)|Sn(s)
Therefore, the cell notation for the voltaic cell with the given reaction is Mg(s)|Mg²⁺(aq)║Sn²⁺(aq)|Sn(s).
Learn more about voltaic cells here:
I hope it helps you!
The process in which a gaseous substance is converted into a condensed, more usable chemical substance is called fixation
Answer:
Tube 2: 8.26 * 10^-3; Tube 4: 6.83 * 10^-5
Explanation:
In the serial dilutions for MIC test, the volume of nutrient broth in each tube should be equal: 5.0 mL. And the volume of agent in each dilution should also be similar: 0.5 mL.
The serial dilutions was as following:
- Tube 1: 0.5/5.5
- Tube 2: 0.5 mL of tube 1 was diluted with 5.0 mL broth. Then, the dilution of tube 2 is (1:11) * (1:11) = (0.5/5.5) * (0.5/5.5) = 1:121 = 8.26 * 10^-3
- Tube 3: We perform the similar calculation. Thus, the result is 1:1331 = 7.51 * 10^-4
- Tube 4: It is 1:14641 = 6.83 * 10^-5.