<span>indicators are weak acids that exist as natural dyes and indicate the concentration of H+ (H3O+) ions in a solution via color change.</span>
Answer:
See Explanation
Explanation:
What Adi failed to realize is that the oily substance that was obtained from lavender consists of a mixture of substances. It is not only the required fragrance that is present in the extract.
This experiment will not work because those other components in the mixture may be erroneously identified when they show up in the mass spectrum of the extract and may be mistaken for the fragrance in question.
Hence the experiment will not work because; if some kind of separation method is not used to identify other impurities in the oil, many other substances may be mistaken for the actual fragrance.
Answer:
Mass of CaCl2 that would dissolve is 24.64g.
Explanation:
Explanation is contained in the picture attached.
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.