This is an incomplete question, here is a complete question.
The rearrangement of methyl isonitrile (CH₃NC) to acetonitrile (CH₃NC) is a first-order reaction and has a rate constant of 5.11 × 10⁻⁵ s⁻¹ at 472 K. If the initial concentration of CH₃NC is 3.00 × 10⁻² M :
How many hours will it take for the concentration of methyl isonitrile to drop to 14.0 % of its initial value?
Answer : The time taken will be, 10.7 hours
Explanation :
Expression for rate law for first order kinetics is given by:

where,
k = rate constant = 
t = time passed by the sample = ?
a = let initial amount of the reactant = 100
a - x = amount left after decay process = 14 % of 100 = 14
Now put all the given values in above equation, we get


Therefore, the time taken will be, 10.7 hours
Answer:
D
Explanation:
Sweat glands remove waste
Expected to deal with what? Fires?
Answer:
Mass of Cl₂ produced 12.78 g
Explanation:
Given data:
Mass of MnO₂ = 16 g
Mass of HCl = 30.0 g
Mass of Cl₂ produced = ?
Solution:
Chemical equation:
MnO₂ + 4HCl → MnCl₂ + Cl₂ + 2H₂O
Number of moles of MnO₂:
Number of moles = mass / molar mass
Number of moles = 16 g/ 87 g/mol
Number of moles = 0.18 mol
Number of moles of HCl:
Number of moles = mass / molar mass
Number of moles = 30 g/ 36.46 g/mol
Number of moles = 0.82 mol
Now we will compare the moles of Cl₂ with MnO₂ and HCl.
MnO₂ : Cl₂
1 : 1
0.18 : 0.18
HCl : Cl₂
4 : 1
0.82 : 1/4×0.82 = 0.205 mol
The number of moles of Cl₂ formed by HCl are less it will limiting reactant.
Mass of Cl₂ formed:
Mass = number of moles × molar mass
Mass = 0.18 mol × 71 g/mol
Mass = 12.78 g