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
geniusboy [140]
3 years ago
12

The rate at which a certain drug is eliminated by the body follows first-order kinetics, with a half life of 81 minutes. Suppose

in a particular patient the concentration of this drug in the bloodstream immediately after injection is 1.8 minutes later? g/mL. What will the concentration be 324 Round your answer to 2 significant digits. x 5 ?
Chemistry
1 answer:
Degger [83]3 years ago
8 0

Answer: 0.11 g/ml

Explanation:

Half-life = 81 minutes

First we have to calculate the rate constant, we use the formula :

k=\frac{0.693}{81\text{minutes}}

k=0.008\text{minutes}^{-1}

Now we have to calculate the age of the sample:

Expression for rate law for first order kinetics is given by:

t=\frac{2.303}{k}\log\frac{a}{a-x}

where,

k = rate constant  = 0.008\text{minutes}^{-1}[/tex]

t = time of decomposition = 324 minutes

a = let initial concentration of the reactant  = 1.8 g/ml

a - x = concentration after decay process  = ?

Now put all the given values in above equation, we get

324=\frac{2.303}{0.008}\log\frac{1.8}{a-x}

(a-x)=0.11g/ml

Thus concentration after 324 minutes will be 0.11 g/ml.

You might be interested in
10. When the pressure on a gas inetcases three times, by how much will the volume incrcase or decrease?
blagie [28]

Answer:The answer to this question comes from experiments done by the scientist Robert Boyle in an effort to improve air pumps. In the 1600's, Boyle measured the volumes of gases at different pressures. Boyle found that when the pressure of gas at a constant temperature is increased, the volume of the gas decreases. when the pressure of gas is decreased, the volume increases. this relationship between pressure and volume is called Boyle's law.

Explanation: So, at constant temperature, the answer to your answer is: the volume decreases in the same ratio as the ratio of pressure increases.

BUT, in general, there is not a single answer to your question. It depend by the context.

For example, if you put the gas in a rigid steel tank (volume is constant), you can heat the gas, so provoking a pressure increase. But you won't get any change in volume.

Or, if you heat the gas in a partially elastic vessel (as a tire or a soccer ball) you will get both an increase of volume AND an increase of pressure.

FINALLY if you inflate a bubblegum ball, the volume will be increased without any change in pressure and temperature, because you have increased the NUMBER of molecules in the balloon.

There are many other ways to change volume and pressure of a gas that are different from the Boyle experiment.

4 0
3 years ago
Which property of a body cannot be changed if a force is applied to it?
prohojiy [21]
The answer is it’s mass
8 0
3 years ago
Read 2 more answers
The percent by mass of bicarbonate (HCO3−) in a certain Alka-Seltzer product is 32.5 percent. Calculate the volume of CO2 genera
nevsk [136]

Answer:

The volume of carbon dioxide gas generated 468 mL.

Explanation:

The percent by mass of bicarbonate in a certain Alka-Seltzer = 32.5%

Mass of tablet = 3.45 g

Mass of bicarbonate =3.45 g\times \frac{32.5}{100}=1.121 mol

Moles of bicarbonate ion = \frac{1.121 g/mol}{61 g/mol}=0.01840 mol

HCO_3^{-}(aq)+HCl(aq)\rightarrow H_2O(l)+CO_2(g)+Cl^-(aq)

According to reaction, 1 mole of bicarbonate ion gives with 1 mole of carbon dioxide gas , then 0.01840 mole of bicarbonate ion will give:

\frac{1}{1}\times 0.01840 mol=0.01840 mol of carbon dioxide gas

Moles of carbon dioxide gas  n = 0.01840 mol

Pressure of the carbon dioxide gas = P = 1.00 atm

Temperature of the carbon dioxide gas = T = 37°C = 37+273 K=310 K

Volume of the carbon dioxide gas = V

PV=nRT (ideal gas equation)

V=\frac{nRT}{P}=\frac{0.01840 mol\times 0.0821 atm L/mol K\times 310 K}{1.00 atm}=0.468 L

1 L = 1000 mL

0.468 L =0.468 × 1000 mL = 468 mL

The volume of carbon dioxide gas generated 468 mL.

5 0
3 years ago
Which of the following does NOT indicate that a chemical change may have taken place?
labwork [276]

The following does NOT indicate that a chemical change may have taken place is fracture formation. A chemical change happens when the substance changes its physical state and composition resulting from a chemical reaction. This chemical reaction may either give off or absorb energy. A change in color is a chemical change. For example, litmus paper turns to red when placed in an acid solution. Production of gas is a chemical change. For example, adding hydrochloric acid to the tiles of the bathroom gives a hissing sound with gases given off. Formation of a precipitate is also a chemical change. Change in shape is not a chemical change.

<span> </span>

3 0
3 years ago
Read 2 more answers
The melting points of alkaline earth metals are many times higher than those of the alkali metals. Explain this difference on th
7nadin3 [17]

The correct answer is higher melting point, bound by metal metal bonds.

While alkali metals only have one valence electron, alkaline earth metals have two. Metal to metal connections hold the metals together. Alkaline earth metals have a stronger metallic connection and a higher melting point because they have two valence electrons.

the characteristics that Group 2 metals excel in over Group 1 metals.

  • Initial Ionization Potential
  • Group 2 items are more difficult than group 1 elements.
  • Strong propensity to produce bivalent compounds

As a result, group 2 metals have stronger metallic bonding, which leads to increased cohesive energy and compact atom packing. This explains why group 2 metals are harder and have higher melting and boiling temperatures than group 1 metals.

To learn more about  Group 2A(2) refer the link:

brainly.com/question/9431096

#SPJ4

3 0
2 years ago
Other questions:
  • Put the following into correct SciNot: 312.5 x 10^20.<br><br>1 point<br><br>Your answer<br><br><br>​
    9·1 answer
  • If you worked at a job for $9.00/hour, what type of correlation is the number of hours worked and your take-home pay?
    12·1 answer
  • AGHHHHHH SOMEONE HELP MEEEEEEEEEEE I WILL RATE BRAINLIEST IF SOMEONE JUST HELPS MEEEEE
    14·1 answer
  • A piece of sodium metal reacts completely with water as follows: 2Na(s) + 2H2O(l) ⟶ 2NaOH(aq) + H2(g) The hydrogen gas generated
    7·1 answer
  • Suppose you wanted to monitor a pH change between 8.7 and 7.7. Which indicator would be most appropriate
    14·1 answer
  • 1<br> What is the mass of 0.328 mol of CO2?
    5·2 answers
  • Calculate the pOH of this solution. pH = 1.90 pOH =
    14·2 answers
  • Na
    13·1 answer
  • There is a third bromobutene structure that could have been formed in the addition of HBr to butadiene: cis-1-bromor-2-butene (t
    12·1 answer
  • Question 6
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!