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3 years ago

What is the technique for calculating the age of remains from the amount of C-14 that is left in once alive living things?

Chemistry

2 answers:

Marizza181 [45]3 years ago

5 0

Carbon 14 dating? is that one of your choices

NeX [460]3 years ago

5 0

Answer:

Radiocarbon dating

Explanation:

The radiocarbon dating method is used in order to determine the age of an object (fossil) by using the unstable radioactive Carbon isotopes. It is very widely used and is efficient for dating objects that are of very recent age.

The half life of Carbon-14 is approximately 5700 years. The half life is defined as the time required to decay half of its original composition. The carbon-14 is an unstable element and after it is completely decayed, it turns into Nitrogen-14, which is a stable element.

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Gaseous ethane will react with gaseous oxygen to produce gaseous carbon dioxide and gaseous water . Supposed 0.301 g of methane

Nina [5.8K]

Answer:

The maximum mass of CO2 that could be produced is 0.1925 grams

Explanation:

Step 1: Data given

Mass of methane = 0.301 grams

Mass of oxygen = 0.28 grams

Molar mass of ethane = 16.04 g/mol

Molar mass of oxygen = 32 g/mol

Step 2: The balanced equation

CH4 + 2O2 → CO2 + 2H2O

For 1 mole methane consumed, we need 2 moles of O2 to produce 1 mole of CO2 and 2 moles of H2O

Step 3: Calculate moles of methane

Number of moles =Mass / Molar mass

Number of moles CH4 = 0.301 grams /16.04 g/mol

Moles CH4 = 0.0188 moles

Step 4: Calculate moles oxygen

Number of moles oxygen = 0.28 grams / 32 g/mol

Moles oxygen = 0.00875 moles

Step 5: the limiting reactant

For 1 mole methane consumed, we need 2 moles of O2

Oxygen is the limiting reactant. It will be completely consumed.

Methane is in excess. There will be consumed 0.00875 /2 = 0.004375 moles

There will remain 0.0188 - 0.004375 = 0.014425 moles

Step 6: Calculate moles of CO2

For 1 mole methane consumed, we need 2 moles of O2 to produce 1 mole of CO2

For 0.00875 moles oxygen , we have 0.004375 moles CO2

Step 7: Calculate mass of CO2

Mass CO2 = moles CO2 * Molar mass CO2

Mass CO2 =0.004375 * 44.01 g/mol = 0.1925 grams CO2

The maximum mass of CO2 that could be produced is 0.1925 grams

8 0

3 years ago

An INPUT of photosynthesis is ______________<br> A.Oxygen<br> B.Roots<br> C.Sunlight

AfilCa [17]

The inputs of photosynthesis are light energy, and matter in the form of water absorbed through the roots, and carbon dioxide absorbed through the leaves.

Therefore an input of photosynthesis from the choices given is,

Sunlight

3 0

3 years ago

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Select the steps that are associated with energy entering the system. Check all that apply.

quester [9]

Answer: option c. the mixing of solute and solvent molecules

Explanation:

8 0

3 years ago

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The conversation of cyclopropane to propene in the gas phase is a first order reaction with a rate constant of 6.7x10-⁴s-¹. a) i

Rus_ich [418]

Answer: a) The concentration after 8.8min is 0.17 M

b) Time taken for the concentration of cyclopropane to decrease from 0.25M to 0.15M is 687 seconds.

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

a - x = amount left after decay process

a) concentration after 8.8 min:

$8.8\times 60s=\frac{2.303}{6.7\times 10^{-4}s^{-1}}\log\frac{0.25}{a-x}$

$\log\frac{0.25}{a-x}=0.15$

$\frac{0.25}{a-x}=1.41$

$(a-x)=0.17M$

b) for concentration to decrease from 0.25M to 0.15M

$t=\frac{2.303}{6.7\times 10^{-4}s^{-1}}\log\frac{0.25}{0.15}\\\\t=\frac{2.303}{6.7\times 10^{-4}s^{-1}}\times 0.20$

$t=687s$

7 0

3 years ago

A ________ reaction occurs when one compound reacts and is broken down into different elements or simpler compounds?

faust18 [17]

Answer: decomposition

Explanation:

1 . Combustion is a type of chemical reaction in which a hydrocarbon reacts with oxygen to form carbon dioxide ans water along with liberation of large amount of energy.

2. Decomposition is a type of chemical reaction in which a single reactant gives two or more than two products.

$CaCO_3\rightarrow CaO+CO_2$

3. Single replacement is a type of chemical reaction in which a more reactive element displaces the less reactive element from its slat solution.

4. Synthesis is a type of chemical reaction in which two or more than two reactants combine together to give a single product.

5 0

3 years ago

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