Answer:
1.88 x 10^5
Explanation:
You have to round because all of the numbers in 187515.4207 are significant
Round to: 188000
Put in scientific notation:
1.88 x 10^5
Answer:
Percent yield = 87.5%
Explanation:
Given data:
Number of moles of Fe(NO₃)₃ = 2.5 mol
Number of moles of Na₂CO₃ = 3.6 mol
Actual yield of NaNO₃ = 6.3 mol
Percent yield of NaNO₃ = ?
Solution:
Chemical equation:
2Fe(NO₃)₃ + 3Na₂CO₃ → Fe₂(CO₃)₃ + 6NaNO₃
now we will compare the moles of both reactant with NaNO₃.
Fe(NO₃)₃ : NaNO₃
2 : 6
2.5 : 6/2×2.5 = 7.5
Na₂CO₃ : NaNO₃
3 : 6
3.6 : 6/3×3.6 = 7.2
Theoretical yield of NaNO₃ is 7.2 mol.
Percent yield:
Percent yield = actual yield / theoretical yield ×100
Percent yield = 6.3 mol / 7.2mol ×100
Percent yield = 87.5%
Answer: lead
Lead has been used for gamma radiation shielding since the discovery of radioactive material & x-ray.
D. Two or more of the same type or different types of atoms.
<u>Answer:</u> The percentage abundance of oxygen-16 isotope is 99.76 %
<u>Explanation:</u>
We are given:
Three isotopes of oxygen are there, O-16, O-17 and O-18
Mass of Oxygen-16 isotope = 15.995 amu
Mass of Oxygen-17 isotope = 16.999 amu
Mass of Oxygen-18 isotope = 17.999 amu
Percentage abundance of Oxygen-17 isotope = 0.04 %
Percentage abundance of Oxygen-18 isotope = 0.2 %
We know that:
Percentage abundance of all isotopes together is 100 %
So, Percentage abundance of Oxygen-16 isotope = [100 - (0.04 + 0.2)] = 99.76 %
Hence, the percentage abundance of oxygen-16 isotope is 99.76 %
