Carbon -14 and Carbon 12 are the two substances geologists use in radiocarbon dating.
Answer: Option B
<u>Explanation:
</u>
Radiocarbon dating denotes the determination process of the age of fossils of plants or animals based on the ratio of carbon atoms 14 to 12. Carbon naturally exists in two non-radioactive isotopes, Carbon-12 and Carbon-13 and one radioactive isotope carbon 14. The carbon 14 gets released on continuous cosmic reaction with atmospheric nitrogen.
These carbon 14 will be absorbed by the living plants and from the plants. Then, it will enter inside the animals which consume the plants. But once the plants and animals died, they ceased to intake carbon-14. In their living state, the ratios of carbon atoms 14 to 12 in them tends to similar to the ratio in atmosphere.
But after they die, the ratio of C-14 to C-12 will be varying from the ratio of C-14 to C-12 in atmosphere as the concentration of C-14 will be decreasing in the dead animals and plants. Thus using this ratio, geologists can find the fossil's age.
Answer:
None of the given options
Explanation:
Let's go case by case:
A. No matter the volume, the concentration of Fe(NO₃)₃ (and thus of [Fe³⁺] as well) is 0.050 M.
B. We can calculate the moles of Fe₂(SO₄)₃:
- 0.020 M * 0.80 L = 0.016 mol Fe₂(SO₄)₃
Given that there are two Fe⁺³ moles per Fe₂(SO₄)₃ mol, in the solution we have 0.032 moles of Fe⁺³. With that information in mind we <u>can calculate [Fe⁺³]</u>:
- 0.032 mol Fe⁺³ / 0.80 L = 0.040 M
C. Analog to case A., the molar concentration of Fe⁺³ is 0.040 M.
D. Similar to cases A and C., [Fe⁺³] = 0.010 M.
Thus none of the given options would have [Fe⁺³] = 0.020 M.
What is reflux? isn't it like when u aren't able to digest something?
Answer:
1.62
Explanation:
From the given information:
number of moles of benzamide 
= 0.58 mole
The molality = 
= 0.6837
Using the formula:
where;
dT = freezing point = 27
l = Van't Hoff factor = 1
kf = freezing constant of the solvent
∴
2.7 °C = 1 × kf × 0.6837 m
kf = 2.7 °C/ 0.6837m
kf = 3.949 °C/m
number of moles of NH4Cl = 
= 1.316 mol
The molality = 
= 1.5484
Thus;
the above kf value is used in determining the Van't Hoff factor for NH4Cl
i.e.
9.9 = l × 3.949 × 1.5484 m
l = 1.62
H+= 10^-14 / [OH-1 = 3.125 * 10^-4 M
pH=-log(H+) = 3.505
Just round it down and your answer = 3.5
