1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Novosadov [1.4K]
3 years ago
5

A first-order reaction has a half-life of 16.7 s . How long does it take for the concentration of the reactant in the reaction t

o fall to one-fourth of its initial value?
Chemistry
1 answer:
andrew11 [14]3 years ago
5 0

It takes 33.4 s for the concentration of A to fall to one-fourth of its original value.

A <em>half-life</em> is the time it takes for the concentration to fall to half its original value.

Assume the initial concentration is 1.00 mol/L. Then,

\text{1.00 mol/L }\stackrel{\text{1st half-life }}{\longrightarrow}\text{ 0.50 mol/L } \stackrel{\text{ 2nd half-life }}{\longrightarrow}\text{0.25 mol/L}\\

The concentration drops to one-fourth of its initial value in two half-lives.

∴ Time = 2 × 16.7 s = 33.4 s

You might be interested in
How many moles of solute are in 250.0 mL of a 3.00 M HCl solution?
cestrela7 [59]
0.250 L*3M=0.250 L*3mol/L= 0.750 mol
8 0
3 years ago
17) A 0.20 M solution of HCl with a volume of 15.0 mL is exactly neutralized by the 0.10 M solution of NaOH with what volume? HI
galina1969 [7]

Answer: A 0.20 M solution of HCl with a volume of 15.0 mL is exactly neutralized by the 0.10 M solution of NaOH with 3 mL volume.

Explanation:

Given: M_{1} = 0.20 M,      V_{1} = 15.0 mL

M_{2} = 0.10 M,            V_{2} = ?

Formula used is as follows.

M_{1}V_{1} = M_{2}V_{2}

Substitute the values into above formula s follows.

M_{1}V_{1} = M_{2}V_{2}\\0.20 M ]times 15.0 mL = 0.10 M ]times V_{2}\\V_{2} = 30 mL

Thus, we can conclude that a 0.20 M solution of HCl with a volume of 15.0 mL is exactly neutralized by the 0.10 M solution of NaOH with 3 mL volume.

4 0
3 years ago
If 5. 0 grams of kcl is dissolved in 500 ml of water, what is the concentration of the resulting solution?
Lady_Fox [76]

If 5.0 grams of KCl is dissolved in 500 ml of water, the concentration of the resulting solution will be 0.134M.

<h3>How to calculate concentration?</h3>

The concentration of a solution can be calculated by using the following formula;

Molarity = no of moles ÷ volume

According to this question, 5.0 grams of KCl is dissolved in 500 ml of water. The concentration is calculated as follows:

no of moles of KCl = 5g ÷ 74.5g/mol = 0.067mol

Molarity = 0.067mol ÷ 0.5L = 0.134M

Therefore, if 5.0 grams of KCl is dissolved in 500 ml of water, the concentration of the resulting solution will be 0.134M.

Learn more about concentration at: brainly.com/question/10725862

#SPJ1

6 0
2 years ago
Which of the following relationships is true?
atroni [7]

Answer:

reeeee

Explanation:

2mnd one

5 0
2 years ago
Which of the following statements is true about fungi? (1 point)
natulia [17]
I'm not sure, but I believe the correct answer is C.
6 0
3 years ago
Other questions:
  • If Hershey and Chase had used radioactive oxygen in their experiments instead of phosphorus and sulfur, what results would they
    13·1 answer
  • The Lewis structures of four compounds are given. In the first molecule sufur is the central atom. There are two oxygen atoms bo
    11·1 answer
  • Calculate the solubility of silver chloride in 0.17M AgNO3. (Ksp=1.8E-10)
    6·1 answer
  • Light elements with an atomic number less than 20 generally have a neutron to proton ratio equal to
    7·1 answer
  • 10.6 grams of Na2CO3 is dissolved in water to make 1.25 liters
    8·1 answer
  • Calculate the pH and fraction of dissociation (
    7·1 answer
  • The process by which water is moved and changed through the earth is called
    7·1 answer
  • Who discovered the electron and what instrument did he use?
    10·1 answer
  • Which of these factors has the greatest influence on how many koala live in an area
    12·1 answer
  • 5. Which type of substance yields hydrogen ions, H+, in
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!