Cs -137 has a half life of about 30 years. If 60 years pass, there is two half lives passed so 1/2 * 1/2= 1/4. Take 1/4 and multiply it with the mass given:
(1/4)*20mg=5mg left
B. both high energy and low energy waves
Answer:
Theoretical yield: 2.75g of paranitroaniline
Percentage yield: 54.5%
Explanation:
In strong-acid medium, acetanilide (Molar mass: 135.16g/mol) reacts producing para-nitroaniline (138.12g/mol) in a 1/1 reaction.
Theoretical yield of para-nitroaniline is the mass produced assuming a yield of 100%. That is:
2.7g acetanilide × (1mol / 135.16g) = 0.020 moles of acetanilide.
Assuming a yield of 100% are 0.020 moles of paranitroaniline. Theoretical yield is:
0.020 moles × (138.12g / mol) =
<h3>Theoretical yield: 2.75g of paranitroaniline</h3><h3 />
Percentage yield is:
(Actual yield / theoretical yield) × 100
Actual yield was 1.5g and percentage yield will be:
Percentage yield: (1.5g / 2.75g) × 100
<h3>Percentage yield: 54.5%</h3>
Answer:
Thus, random error primarily affects precision. Typically, random error affects the last significant digit of a measurement. The main reasons for random error are limitations of instruments, environmental factors, and slight variations in procedure.
Explanation:
