Answer:
Percent yield = 90.9%
Explanation:
Given data:
Mass of CaCO₃ = 50.0 g
Mass of CO₂ produced = 20.0 g
Percent yield = ?
Solution:
Chemical equation:
CaCO₃ → CaO + CO₂
Number of moles of CaCO₃:
Number of moles = mass/molar mass
Number of moles = 50.0 g/ 100.1 g/mol
Number of moles = 0.5 mol
Now we will compare the moles of CO₂ with CaCO₃.
CaCO₃ : CO₂
1 : 1
0.5 : 0.5
Mass of CO₂: Theoretical yield
Mass = number of moles × molar mass
Mass = 0.5 mol × 44 g/mol
Mass = 22 g
Percent yield:
Percent yield = ( actual yield / theoretical yield ) × 100
Percent yield = (20.0 g/ 22.0 g) × 100
Percent yield = 0.909 × 100
Percent yield = 90.9%
Which of the following terms best describes the nucleus of a radioactive element?
C. Unstable
(2) U-238 is the radioisotope used in dating geological formations. Uranium-238 has a half-life of 4.46 billion years, which makes it suitable to date such old formations.
The other options do not have such long durabilities and half-lives.
I think it is <span>0.823 g H2O+NH3/1 ml H2O+NH3 17.034 g NH3/1 mol 18.016 g H2O/1 mol 0.87 mol NH3/1 kg H2O</span>
