A first order reaction, with a half-life of 125 s, has 1/16 of the original amount left after 500 seconds.
<h3>What is a first order reaction?</h3>
It is a chemical reaction in which the rate of reaction is directly proportional to the concentration of the reacting substance.
First, we will calculate the rate constant using the following expression.
ln ([A]/[A]₀) = - k × t
ln (1/16[A]₀/[A]₀) = - k × 500 s
k = 5.55 × 10⁻³ s⁻¹
where,
- [A] is the final concentration of the reactant.
- [A]₀ is the initial concentration of the reactant.
- k is the rate constant.
- t is the elapsed time.
Next, we can calculate the half-life (th) using the following expression.
th = ln 2 / k = ln 2 / (5.55 × 10⁻³ s⁻¹) = 125 s
A first order reaction, with a half-life of 125 s, has 1/16 of the original amount left after 500 seconds.
Learn more about first order reactions here: brainly.com/question/518682
Answer:
There are three types of DNA Mutations: base substitutions, deletions and insertions. Single base substitutions are called point mutations, recall the point mutation Glu -----> Val which causes sickle-cell disease. Point mutations are the most common type of mutation and there are two types.
Explanation:
<span>Compounds with stronger inter molecular forces have higher boiling points.
Methanol has strong hydrogen bonds. It will have the next highest boiling point.
CH4, has the lowest boiling point.
The order of strengths of intermolecular forces is:
ion-ion > H-bonding > dipole-dipole > London dispersion
.</span>
Sodium acetate is a type<span> of salt. When water is added to sodium acetate, the chemical bonds break down, causing it to separate into sodium ions and acetate ions. </span>
Answer:
(A) 0.80 M
(B) 0.64 g
(C) 0.050 M
(D) 1.6 M
Explanation:
(A)
Convert 4.0 g to moles with molar mass. Convert 125 mL to L.
4.0 g x (1 mol/39.998 g) = 0.100 mol
125 mL x (1 L/1000 mL) = 0.125 L
Molarity = mol/L
Molarity = 0.100 mol/0.125 L = 0.80 M
(B)
Find moles of NaOH with the molarity you just found. And convert 20 mL to L.
Molarity = mol/L
0.80 M = mol/0.020 L
mol = 0.016
Convert moles to grams with molar mass.
0.016 mol x (39.998 g/1 mol) = 0.64 g
(C)
You know the molarity of a NaOH solution (Part A). 30 mL initial volume and 480 mL final volume are given. Dilution question so use the dilution formula.
M1V1 = M2V2
(0.80 M)(30 mL) = (M2)(480 mL)
M2 = 0.050 M
(D)
Dilution question again, use the dilution formula.
M1V1 = M2V2
(0.80 M)(200 mL) = (M2)(100 mL)
M2 = 1.6 M