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
dezoksy [38]
3 years ago
14

The half-life of gold-198 is 2.7 days. After

Chemistry
1 answer:
Pie3 years ago
8 0

Answer: 8.1 days

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

t = age of sample

a = let initial amount of the reactant = x

a - x = amount left after decay process= \frac{x}{4} 

a) to find rate constant

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

t_{\frac{1}{2}}=\frac{0.693}{k}

k=\frac{0.693}{2.7days}=0.257days^{-1}

b) for completion of one fourth of reaction

t=\frac{2.303}{k}\log\frac{x}{\frac{x}{4}}

t=\frac{2.303}{0.257}\log{4}

t=8.1days

Thus after 8.1 days , one fourth of original amount will remain.

You might be interested in
What is the total pressure exerted by a mixture containing two gases if the partial
nikdorinn [45]

Answer: 100 torr

Explanation:

8 0
3 years ago
A gas bubble has a volume of 0.650 mL at the bottom of a lake, where the pressure is
astraxan [27]

Considering the Boyle's law, as the pressure decreases, volume increases and has a value of 2.246 mL.

<h3>Boyle's law</h3>

Boyle's law establishes the relationship between the pressure and the volume of a gas when the temperature is constant.

This law says that the volume occupied by a given mass of gas at constant temperature is inversely proportional to the pressure. This means that if the pressure increases, the volume decreases, while if the pressure decreases, the volume increases.

Boyle's law is expressed mathematically as:

P×V=k

If an initial state 1 and a final state 2 are analyzed, Boyle's law is expressed as:

P1×V1=P2×V2

<h3>Volume at the surface of the lake</h3>

In this case, you know:

  • P1= 3.46 atm
  • V1= 0.650 mL
  • P2= 1 atm
  • V2= ?

Replacing in Boyle's law:

3.46 atm× 0.650 mL= 1 atm×V2

Solving:

V2= (3.46 atm× 0.650 mL)÷ 1 atm

<u><em>V2= 2.246 mL</em></u>

Finally, as the pressure decreases, volume increases and has a value of 2.246 mL.

Learn more about Boyle's law:

brainly.com/question/4147359

#SPJ1

4 0
2 years ago
A spectrophotometer measures the transmittance or the absorbance, or both, of a particular wavelength of light after it has pass
Cerrena [4.2K]

Answer:Answer: The step that is NOT necessary to complete before a cuvette is placed into the spectrophotometer is option B (Write, in ink, either sample or blank on the side of the cuvette to keep track of them)

Explanation: spectrophotometer is an instrument used to measure the light intensity absorbed after being passed through a solution. Before the absorbance of the sample solution, a solvent solution called blank is used for the calibration of the machine and this blank solvent is placed in a cuvette. The procedure usually comes first before the main sample is processed. Therefore there is no need to

Write, in ink, either sample or blank on the side of the cuvette to keep track of them. This is so since sample and blank is not absorbed at the same time by the machine.

7 0
3 years ago
Read 2 more answers
A sample of gas contains 0.1700 mol of OF2(g) and 0.1700 mol of H2O(g) and occupies a volume of 19.5 L. The following reaction t
andreev551 [17]

Answer: The volume of the sample after the reaction takes place is 29.25 L.

Explanation:

The given reaction equation is as follows.

OF_{2}(g) + H_{2}O(g) \rightarrow O_{2}(g) + 2HF(g)

So, moles of product formed are calculated as follows.

\frac{3}{2} \times 0.17 mol \\= 0.255 mol

Hence, the given data is as follows.

n_{1} = 0.17 mol,      n_{2} = 0.255 mol

V_{1} = 19.5 L,         V_{2} = ?

As the temperature and pressure are constant. Hence, formula used to calculate the volume of sample after the reaction is as follows.

\frac{V_{1}}{n_{1}} = \frac{V_{2}}{n_{2}}

Substitute the values into above formula as follows.

\frac{V_{1}}{n_{1}} = \frac{V_{2}}{n_{2}}\\\frac{19.5 L}{0.17 mol} = \frac{V_{2}}{0.255 mol}\\V_{2} = \frac{19.5 L \times 0.255 mol}{0.17 mol}\\= \frac{4.9725}{0.17} L\\= 29.25 L

Thus, we can conclude that the volume of the sample after the reaction takes place is 29.25 L.

8 0
3 years ago
HELP ASAP! GIVING BRAINLIEST!! 15 POINTS
Rufina [12.5K]

I think Kinetic energy forms <em>Motion energy </em>and Potential energy forms <em>Gravitational Potential energy.</em>

5 0
3 years ago
Other questions:
  • What are fragments of dust, soil, salt, smoke and ash upon which water vapor condenses to make clouds
    15·2 answers
  • Jidkcusuwjxjfuieieidieiriririeir
    5·1 answer
  • One container is filled with argon gas and the other with krypton gas. If both gases have the same temperature, in which contain
    12·1 answer
  • Give the formulas for the ionic compounds made of the following ions:
    9·1 answer
  • Considering the IMA of this frictionless inclined plane, how much force is required to drag a 90 lb. box up it?
    12·1 answer
  • How many isotopes does argon have?
    6·1 answer
  • How many moles are in 5.34 x 10*21 particles of Nitrogen?
    15·1 answer
  • Check wether all the answers are correct or not. please?​
    14·2 answers
  • What is the boiling point for water in degrees celsius?
    9·1 answer
  • Which body part MOST LIKELY formed this fossil?<br> blood<br> B<br> bones<br> fur<br> D<br> skin
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!