Answer:
7.5 sec.
Explanation:
A = A₀e⁻^kt => k = ln(A/A₀)/-t => ln(6.25/100)/-30s = 0.0924 s⁻¹
k·t₀.₅=0.693 => t₀.₅=0.693/k = (0.693/0.0924)s = 7.5 s
I don't know if this helps...but it is a titration formula.
Matter buddy, ur welcome :)
29.26 gram
Explanation:
No of molecules = no of mole × Avogadro's number
No of molecules = mass in gram/ molar mass × Avogadros number
Mass in gram =No of molecules×molar mass / Avogadros number
Mass in gram = 3.012 ×10^23 × 58.5/6.02×10^23
29.26 gram