Answer:
is the activity, measured in of a 50 mg sample of 90-Sr.
Explanation:
Half life of the 90-Sr ,
Activity coefficient of the 90-Sr =
Mass of 90-Sr = 50 mg = 0.050 g
Molecular mass of 90-Sr = 90 g/mol
Moles of 90-Sr =
Number of atom in 0.0005555 moles of 90-Sr:
1 year =
Activity measured in atoms per seconds:
= Number of atoms ×
The molarity of the HCl is 1 M when 12.0 of .500 M NaOH neutralized 6.0 ml of HCl solution.
Explanation:
Data given:
molarity of the base NaOH, Mbase =0. 5 M
volume of the base NaOH, Vbase = 12 ml
volume of the acid, Vacid = 6 ml
molarity of the acid, Macid = ?
The titration formula for acid and base is given as:
Mbase Vbase = Macid Vacid
Macid =
Macid = 1 M
we can see that 1 M solution of HCl was used to neutralize the basic solution of NaOH. The volume of NaOH is 12 ml and volume of HCl used is 6ml.