Answer:
the answer of this question is 0.000058
Explanation:
According to the analysis, Molarity is amount mole per volume(1L). the amount in mole would be molarity × volume in litres.
0.500M × (250/1000)L= 0.125moles.
I hope this helps**
Answer: The rate constant is
Explanation ;
Expression for rate law for first order kinetics is given by:

where,
k = rate constant = ?
t = age of sample = 4.26 min
a = initial amount of the reactant = 2.56 mg
a - x = amount left after decay process = 2.50 mg
Now put all the given values in above equation to calculate the rate constant ,we get



Thus rate constant is [tex]0.334s^{-1}
Mole ratio for the reaction is 1:1
no of moles in NaOH that reacted= 1*21.17/1000=0.02117mols
molarity of HCl=0.02117*10/1000
=2.117M