Answer:
final concentration: Ca = 0.014 M
Explanation:
Velocity of reaction:
∴ α: order of reaction, assuming α = 1
∴ K = 0.249 s-1.......rate constant
∴ Cao = 0.050 M......initial concentration
∴ t = 5 s.......reaction time
⇒ δCa/δt = K*Ca
⇒ ∫δCa/Ca = K*∫δt
⇒ Ln(Cao/Ca) = K*t = (0.249s-1)(5 s) = 1.245
⇒ Cao/Ca = 3.473
⇒ Ca = 0.050/3.473
⇒ Ca = 0.014 M
B - A chemist might determine the fat content in a candy bar.
1) Fatty acids stored in candy bars are (in fact) composed of chemical substances.
2) Choice A makes no sense. This activity belongs in the Biology field. Or if you're an animal activist, you might be interested in undertaking this as a hobby.
3) Choice C is absurd because either you're a Physicist who enjoys an occupation such as this, or you're just plain crazy.
4) Choice D is preposterous because either you're a Meteorologist, or a Geoscientist. Both of which have nothing to do with chemistry.
1. U₂₃₈→α→Th₂₃₄(UX₁)
<span>2. Th₂₂₈→α→Ra₂₂₆(MsTh₁) </span>
<span>α = Alpha decay (release of He Nucleus) </span>
<span>The decay products are meso states that undergo further (β) decay</span>
Answer: (3) carbon dioxide
Explanation: Solubility of solids and liquids is not affected by pressure as they are highly incompressible. Methanol is liquid, carbon dioxide is a gas, sugar is a solid and sodium nitrate is also a solid.
But solubility of gases is affected by pressure as they are compressible and the solubility is governed by Henry's law, which states that mass of gas dissolved in a given liquid ta constant temperature is directly proportional to the pressure of the gas present in equilibrium with the liquid.
Increase in pressure increases the solubility as increase in pressure would lead to decrease in volume of gas particles and hence more number of particles will be present per unit volume and as a result, the number of particles striking the surface of solution and entering the solution will increase. Thus solubility increases.
Explanation:
Ksp of NiCO3 = 1.4 x 10^-7
Ksp of CuCO3 = 2.5 x 10^-10
Ionic equations:
NiCO3 --> Ni2+ + CO3^2-
CuCO3 --> Cu2+ + CO3^2-
[Cu2+][CO3^2-]/[Ni2+][CO3^2-]
= (2.5* 10^-10)/(1.4* 10^-7)
= 0.00179.
[Cu2+]/[Ni2+]
= 0.00179
= 0.00179*[Ni2+]
If all of Cu2+ is precipitated before Na2CO3 is added.
= 0.00179 * (0.25)
The amount of Cu2+ not precipitated = 0.000448 M
The percent of Cu2+ precipitated before the NiCO3 precipitates = concentration of Cu2+ unprecipitated/initial concentration of Cu2+ * 100
= 0.000448/0.25 * 100
= 0.18%
Therefore, percentage precipitated = 100 - 0.18
= 99.8%
The two metal ions can be separated by slowly adding Na2CO3. Thus that is the unpptd Cu2+.
