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3 years ago

Scientists think the earth is approximately _____ years old.

Chemistry

2 answers:

gizmo_the_mogwai [7]3 years ago

5 0

Scientist thinks the earth is approximately 4 1/2 years old.

diamong [38]3 years ago

4 0

Answer is 4 ½ billion.

Scientists think the earth's age is 4 ½ billion. This calculation is based on the radioactive dating. Since the formation of the earth, the time period has been divided into 3 major geological time periods as eon. They are phanerozoic, proterozoic and archean.

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Compare and contrast steak and juice

blsea [12.9K]

Steak is a meat and juice is a liquid

5 0

3 years ago

Determine the empirical and molecular formula for chrysotile asbestos. Chrysotile has the following percent composition: 28.03%

nlexa [21]

Answer: The empirical and molecular formula of chrysotile is $Mg_3Si_2H_3O_4$ and $Mg_6Si_4H_6O_{16}$

Explanation:

We are given:

Percentage of Mg = 28.03 %

Percentage of Si = 21.60 %

Percentage of H = 1.16 %

Percentage of O = 49.21 %

Let the mass of compound be 100 g. So, percentages given are taken as mass.

Mass of Mg = 28.03 g

Mass of Si = 21.60 g

Mass of H = 1.16 g

Mass of O = 49.21 g

To formulate the empirical formula, we need to follow some steps:

Step 1: Converting the given masses into moles.

Moles of Magnesium = $\frac{\text{Given mass of Magnesium}}{\text{Molar mass of Magnesium}}=\frac{28.03g}{24g/mole}=1.17moles$

Moles of Silicon = $\frac{\text{Given mass of Silicon}}{\text{Molar mass of Silicon}}=\frac{21.06g}{28g/mole}=0.752moles$

Moles of Hydrogen = $\frac{\text{Given mass of Hydrogen}}{\text{Molar mass of Hydrogen}}=\frac{1.16g}{1g/mole}=1.16moles$

Moles of Oxygen = $\frac{\text{Given mass of oxygen}}{\text{Molar mass of oxygen}}=\frac{49.21g}{16g/mole}=3.07moles$

Step 2: Calculating the mole ratio of the given elements.

For the mole ratio, we divide each value of the moles by the smallest number of moles calculated which is 0.752 moles.

For Magnesium = $\frac{1.17}{0.752}=1.5$

For Silicon = $\frac{0.752}{0.752}=1$

For Hydrogen = $\frac{1.16}{0.752}=1.5$

For Oxygen = $\frac{3.07}{0.485}=4.08\approx 4$

To convert the mole ratios into whole numbers, we multiply individual mole ratios by 2

Mole ratio of Magnesium = (2 × 1.5) = 3

Mole ratio of Silicon = (2 × 1) = 2

Mole ratio of Hydrogen = (2 × 1.5) = 3

Mole ratio of Oxygen = (2 × 4) = 8

Step 3: Taking the mole ratio as their subscripts.

The ratio of Mg : Si : H : O = 3 : 2 : 3 : 8

The empirical formula for the given compound is $Mg_3Si_2H_3O_8$

For determining the molecular formula, we need to determine the valency which is multiplied by each element to get the molecular formula.

The equation used to calculate the valency is :

$n=\frac{\text{Molecular mass}}{\text{Empirical mass}}$

We are given:

Mass of molecular formula = 520.8 g/mol

Mass of empirical formula = [(24 × 3) + (28 × 2) + (1 × 3) + (16 × 8)] = 259 g/mol

Putting values in above equation, we get:

$n=\frac{520.8g/mol}{259g/mol}=2$

Multiplying this valency by the subscript of every element of empirical formula, we get:

$Mg_{(3\times 2)}Si_{(2\times 2)}H_{(3\times 2)}O_{(8\times 2)}=Mg_6Si_4H_6O_{16}$

Hence, the empirical and molecular formula of chrysotile is $Mg_3Si_2H_3O_4$ and $Mg_6Si_4H_6O_{16}$

5 0

3 years ago

Which consequence of global warming is described as having an increase in growing season changes in migration and loss of specie

IgorLugansk [536]

Answer:

Deforestation, increase wildlife extinction, ecosystem imbalances, soil erosion, migration and loss of species.

Explanation:

Global warming is warming the earth's surface temperature, which causes the changes in our ecosystem like deforestation, soil erosion, climate changes, migration and loss of species etc.

Global warming is caused by the 'Greenhouse effect', major gases are carbon dioxide(9-26%), methane(4-9%), water vapour(36-70%) ozone(3-7%) and nitrous oxide.

Global warming affects on the ocean include rising sea level, meiting glaciers, thermal expansion and ice sheets. It also cause the bird migration which carries high cost of predation and mortality.

8 0

3 years ago

Read 2 more answers

Study this chemical reaction: (aq)(s)(s)(aq) Then, write balanced half-reactions describing the oxidation and reduction that hap

disa [49]

The question is incomplete, complete question is:

Study this chemical reaction:

$FeSO_4 (aq) + Zn (s)\rightarrow Fe (s) + ZnSO_4 (aq)$

Then, write balanced half-reactions describing the oxidation and reduction that happen in this reaction.

Oxidation:

Reduction:

Answer:

Oxidation taking place in given reaction :

$Zn(s)\rightarrow Zn^{2+}+2e^-$

Reduction taking place in given reaction;

$Fe^{2+}(aq)+2e^-\rightarrow Fe(s)$

Explanation:

Redox reaction is defined as the reaction in which oxidation and reduction reaction occur side by side.

Oxidation reaction is defined as the chemical reaction in which an atom looses its electrons. The oxidation number of the atom gets increased during this reaction.

$X\rightarrow X^{n+}+ne^-$

Reduction reaction is defined as the chemical reaction in which an atom gains electrons. The oxidation number of the atom gets reduced during this reaction.

$X^{n+}+ne^-\rightarrow X$

$FeSO_4 (aq) + Zn (s) \rightarrow Fe (s) + ZnSO_4 (aq)$

In the given reaction, iron(II) ions are getting reduced and zinc metal is getting oxidized to zinc(II) ions.

Oxidation :

$Zn(s)\rightarrow Zn^{2+}+2e^-$

Reduction ;

$Fe^{2+}(aq)+2e^-\rightarrow Fe(s)$

6 0

2 years ago

Explain why warm nitric acid is used

Schach [20]

Answer:

Lead is added to warm dilute nitric acid. When the carbonate has reacted with the warm acid, more carbonate is added until the carbonate is in excess.

Explanation:

8 0

2 years ago

Read 2 more answers