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
otez555 [7]
2 years ago
13

If a tree dies and the trunk remains undisturbed for 13,750 years, what percentage of the original 14c is still present? (the ha

lf-life of 14c is 5730 years.)
Chemistry
1 answer:
defon2 years ago
8 0

Answer:

18.94%.

Explanation:

  • The decay of carbon-14 is a first order reaction.
  • The rate constant of the reaction (k) in a first order reaction = ln (2)/half-life = 0.693/(5730 year) = 1.21 x 10⁻⁴ year⁻¹.
  • The integration law of a first order reaction is:

<em>kt = ln [A₀]/[A]</em>

k is the rate constant = 1.21 x 10⁻⁴ year⁻¹.

t is the time = 13,750 years.

[A₀] is the initial percentage of carbon-14 = 100.0 %.

[A] is the remaining percentage of carbon-14 = ??? %.

∵ kt = ln [Ao]/[A]

∴ (1.21 x 10⁻⁴ year⁻¹)(13,750 years) = ln (100.0%)/[A]

1.664 =  ln (100.0%)/[A]

Taking exponential for both sides:

5.279 = (100.0%)/[A]

<em>∴ [A]</em> = (100.0%)/5.279 = <em>18.94%.</em>

You might be interested in
What kind of chemical reaction does the chemical equation sodium + chlorine → sodium chloride represent? A. combustion B. decomp
KatRina [158]

Answer:

d. synthesis

Explanation:

it uses the formula a+b=ab.

8 0
3 years ago
Suppose 0.274 mol of a gas occupy 6.62 l at a given temperature and pressure. what volume will 0.878 mol occupy at the same temp
Taya2010 [7]
The  volume  that    0.878  mol  occupy  at   the  same   temperature  and  pressure   is  calculated  as follows


if   0.274  mol  occupy  6.62 L  what  about  0.878  mol

by   cross   multiplication

=0.878 x6.62/0.274=21.21 L
6 0
3 years ago
If 3.5 moles of nitrogen monoxide (NO) react with 6.0 moles of oxygen gas (O2), how many moles of the product can be formed and
jasenka [17]

Answer: -

4.25 mol of O₂ left as excess.

3.5 mol of NO₂ formed.

Explanation: -

Number of moles of NO taken = 3.5

Number of moles of O₂ taken = 6.0

The balanced chemical equation for this reaction is

2 NO+ O₂ → 2 NO₂

From the equation we can see that

2 mol of NO react with 1 mol of O₂

3.5 mol of NO react with \frac{1 mol O2}{2 mol NO} x 3.5 mol NO

= 1.75 mol O₂

So Oxygen O₂ is in excess and NO is the limiting reagent.

Moles of O₂ left over = 6 - 1.75 =4.25 mol of O₂

From the balanced chemical equation we see

2 mol of NO gives 2 mol of NO₂

3.5 mol of NO gives\frac2 mol NO2}{2 mol NO} x 3.5 mol NO

= 3.5 mol of NO₂

5 0
2 years ago
How few drops formed?​
Alja [10]

A drop may form when liquid accumulates at the lower end of a tube or other surface boundary, producing a hanging drop called a pendant drop. Drops may also be formed by the condensation of a vapor or by atomization of a larger mass of liquid.

8 0
2 years ago
There are three main parts to any dissolution which result in an energy change, either endothermic or exothermic. Consider the d
valkas [14]

Answer:

The dissolution of sodium chloride involves three steps. During the process energy changes occur in:

1. breaking apart the hydrogen bonds between water molecules,

2. breaking apart the electrostatic bonds between sodium and chloride ions, and

3. when bonds are formed between water molecules and aqueous ions in solution.

Since the energy used to break apart the hydrogen bonds between water molecules and the energy used to break apart the electrostatic bonds between sodium and chloride ions, is greater than the energy released when bonds are formed between water molecules and aqueous ions in solution, the dissolution of sodium chloride is endothermic.

Explanation:

The heat of solution or enthalpy of solution/dissolution, is the enthalpy change that occurs with the dissolution of a solute in a solvent at constant pressure, resulting in infinite dilution. Its unit is kJ/mol for reactions taking place under standard conditions (298.15 K and 1 atm).

The process of dissolution occurs in three energy-dependent steps:  

1. The breaking of bonds within the solute. For example, electrostatic forces of attraction between two oppositely-charged ions. This process is endothermic.

2. The endothermic process of breaking of intermolecular forces within the solvent, e.g. hydrogen bonds in water.

3. The exothermic process of the formation of new solute-solvent bonds in solution.

The sum of the energies involved in these three steps gives the enthalpy of dissolution of a solute. The overall process of dissolution can either endothermic or exothermic depending on the amount of energy used or released in breaking and making bonds. If more energy is released in making than is used in breaking bonds, it is exothermic.  However, if more energy is used in breaking bonds than is released in making bonds, dissolution is then endothermic.

<em>For example, considering the dissolution of sodium chloride. During the process the energy used to break apart the hydrogen bonds between water molecules and the energy used to break apart the electrostatic bonds between sodium and chloride ions, is greater than the energy released when bonds are formed between water molecules and aqueous ions in solution. Therefore, the dissolution of sodium chloride is endothermic. </em>

<em />

3 0
3 years ago
Other questions:
  • The melting point of copper is 1084 Celsius. How does the energy of the particles in a certain amount of liquid copper compare t
    9·1 answer
  • Lewis structure for CO2
    10·2 answers
  • Which factors are needed to determine the amount of heat absorbed by an aluminum cube after it is warmed?
    5·1 answer
  • How is iodine-131 the same as iodine-126
    5·1 answer
  • The burning of gasoline to power internal combustion engines produces water vapor, and carbon dioxide gas that is thought to con
    15·2 answers
  • At 7 degrees Celsius the volume of gas is 49 liters. At the same pressure its volume is 74 mL at what temperature
    12·1 answer
  • What is the name given to the property of metal that allows electricity to pass through.
    10·2 answers
  • Briefly explain in your own words why the bond angle increases as the number of electron groups decreases
    14·1 answer
  • A sample of krypton occupies 15.0 L at a pressure of 2.1 atm. Use Boyle's Law to find the pressure of the krypton when the volum
    6·1 answer
  • A blue whale has a length of 28,578 millimeters. What is the length of a blue whale in kilometers? Show your work below by writi
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!