I don't know terribly much about radioactive decay, but yes, it WILL decay. If it's half life is 25 days, it will be completely consumed in 50 days. By 100 days, it should be long gone. As far as I know, the reason for this is (besides the simple math which is self-explanatory) the Thorium has so many protons/neutrons, it's unstable and thus undergoes radioactive decay as it cannot maintain stable form.
I hope this helps! :)
Answer:
0.00676 M
Explanation:
A chemist prepares a solution of calcium bromide by weighing out 0.607g of calcium bromide into a 450ml volumetric flask and filling the flask to the mark with water. Calculate the concentration in mol/L of the chemist's calcium bromide solution. Be sure your answer has the correct number of significant digits.
Step 1: Given data
Mass of calcium bromide (solute): 0.607 g
Volume of solution: 450 mL
Step 2: Calculate the moles corresponding to 0.607 g of calcium bromide
The molar mass of CaBr₂ is 199.89 g/mol.
0.607 g × 1 mol/199.89 g = 0.00304 mol
Step 3: Convert the volume of solution to liters
We will use the conversion factor 1 L = 1000 mL.
450 mL × 1 L/1000 mL = 0.450 L
Step 4: Calculate the molar concentration of calcium bromide
The molarity of the solution is:
M = moles of solute / liters of solution
M = 0.00304 mol / 0.450 L
M = 0.00676 M
Do DIMENSIONAL Analysis what comes up must come down
Answer:
At the second equivalent point 200 mL of NaOH is required.
Explanation:
at the first equivalent point:
H2A + OH- = HA- + H2O
initial mmoles y*100 y*100 - -
final mmoles 0 0 y*100 y*100
at the second equivalent point:
HA- + OH- = A2- + H2O
initial mmoles y*100 y*100 - -
final mmoles - - y*100 y*100
at the second equivalent point we have that y*100 mmoles of NaOH or 100 mL of NaOH ir required, thus:
at the second equivalent point 200 mL of NaOH is required.
