A. The radioactive decay equation is N = N0
where T is the half-life (5730 years), N0 is the number of atoms at time t = 0 and N is the number at time t.
Rewriting this as:
(N/N0) =
Since N = (1/8) N0 and substituting known values:
1/8 =
Taking ln of both sides:
ln(1/8)= -ln(2)*t/5730
t = - 5730 * ln(1/8) / ln (2)
t = 17,190 years
The tree was cut down 17,190 years ago.
B. N0 = 1,500,000 carbon-14 atoms
Since N = (1/8) N0
N = 187,500 carbon atoms left
<u>Answer:</u> The mass of original oxalic acid sample is 6.75 grams
<u>Explanation:</u>
To calculate the concentration of acid, we use the equation given by neutralization reaction:
where,
are the n-factor, molarity and volume of acid which is
are the n-factor, molarity and volume of base which is NaOH.
We are given:
Putting values in above equation, we get:
To calculate the mass of solute, we use the equation used to calculate the molarity of solution:
Given mass of oxalic acid = ? g
Molar mass of oxalic acid = 90 g/mol
Molarity of solution = 0.075 M
Volume of solution = 1.00 L
Putting values in above equation, we get:
Hence, the mass of original oxalic acid sample is 6.75 grams