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
Tatiana [17]
3 years ago
15

Assume that you have developed a tracer with first-order kinetics and k = 0.1 s − 1 . For any given mass, how long will it take

the tracer concentration to drop by (a) 50% and (b) by 75%?
Chemistry
1 answer:
anygoal [31]3 years ago
5 0

Answer: It will take 6.93 sec for tracer concentration to drop by 50% and 13.9 sec for tracer concentration to drop by 75%

Explanation:

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  =0.1s^{-1}

t = age of sample  

a = let initial amount of the reactant  = 100 g

a - x = amount left after decay process  

a) for tracer concentration to drop by 50%

a - x = amount left after decay process   = 50

t=\frac{2.303}{k}\log\frac{100}{50}

t=\frac{0.693}{0.1}

t=6.93sec

It will take 6.93 sec for tracer concentration to drop by 50%

b) for  tracer concentration to drop by 75 %

a - x = amount left after decay process   = 25

t=\frac{2.303}{k}\log\frac{100}{100-75}

t=\frac{2.303}{0.1}\times \log\frac{100}{25}

t=13.9sec

It will take 13.9 sec for tracer concentration to drop by 75%.

You might be interested in
Looters break a statue into pieces. How do you expect the weathering of pieces of rock to change?
andreyandreev [35.5K]
The statue will weather faster because of more surface area.
5 0
3 years ago
Which of these is an indication that a chemical reaction has occurred?
nevsk [136]

Formation Of A Gas.

3 0
3 years ago
A 44.0 g sample of an unknown metal at 99.0 oC was placed in a constant-pressure calorimeter of negligible heat capacity contain
tatiyna

Answer:

C_m=0.474\frac{J}{g\°C}

Explanation:

Hello.

In this case, since this is a system in which the water is heated up and the metal is cooled down in a calorimeter which is not affected by the heat lose-gain process, we can infer that the heat lost by the metal is gained be water, it means that we can write:

Q_m=-Q_w

Thus, in terms of masses, specific heats and temperatures we can write:

m_mC_m(T_{eq}-T_m)=-m_wC_w(T_{eq}-T_w)

Whereas the equilibrium temperature is the given final temperature of 28.4 °C and we can compute the specific heat of the metal as shown below:

C_m=\frac{-m_wC_w(T_{eq}-T_w)}{m_m(T_{eq}-T_m)}

Plugging the values in and since the density of water is 1.00 g/mL so the mass is 80.0g, we obtain:

C_m=\frac{-80.0g*4.184\frac{J}{g\°C} (28.4\°C-24.0\°C)}{44.0g(28.4\°C-99.0\°C)}\\\\C_m=0.474\frac{J}{g\°C}

Best regards!

6 0
2 years ago
Which of these is an example of physical change
Julli [10]

Answer:

it is A mark me big brain pls

Explanation:

5 0
2 years ago
Read 2 more answers
Which of the following compounds is a gas at room temperature? A : CH3CH2OH B : CH3CH2CH2CH2CH2CH2CH3 C : CH3CH2CH3 D : HOCH2CH2
attashe74 [19]

Answer:

C. CH_3CH_2CH_3

Explanation:

Molecules with the stronger intermolecular forces are pulled tightly together  to form solid at higher temperatures and that's why the freezing point is higher.

Also, molecules with the stronger intermolecular force have greater interaction between the molecules and thus on heating do not boil easily and have high boiling point also.

Thus, melting point and boiling point increases with increase in number of carbon atoms and also increase in intermolecular forces (like hydrogen bonding, if present).

Thus, the compound which is gas at room temperature is CH_3CH_2CH_3 <u>because it has least number of carbon atoms and absence of hydrogen bonding.</u>

<u></u>

8 0
3 years ago
Other questions:
  • In an atomic model that includes a nucleus, positive charge is
    6·1 answer
  • Which of the following gases would diffuse the fastest? <br> CH 4<br> CCl 4 <br> O 2<br> H 2
    13·1 answer
  • What number is missing from this nuclear equation?
    10·2 answers
  • Express the frequency in inverse seconds of n=4 to n=3
    14·1 answer
  • What is the formula for calculating the speed
    12·2 answers
  • N the reaction Mg + 2HCl -&gt; MgCl2 + H2 which element’s oxidation number does not change?
    8·1 answer
  • A cylinder contains 3.1 L of oxygen at 300 K and 2.7 atm. The gas is heated, causing a piston in the cylinder to move outward. T
    7·1 answer
  • Can someone help me pleasee
    12·1 answer
  • Using the weather radar map shown here, infer at which lettered point the most likely tornado formation and damage would
    10·2 answers
  • What are the parts of a chromosome
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!