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2 years ago

What are the 4 most abundant minerals in the continental crust? What percentage do these 4 makeup of the total?

Chemistry

1 answer:

Tanya [424]2 years ago

5 0

Answer:

$SiO_2$ , $Al_2O_3$ , $CaO$ , $MgO$

Explanation:

The four most abundant minerals in the continental crust are, $SiO_2$ , $Al_2O_3$ , $CaO$ , $MgO$ .

The percentages are

$SiO_2=60.6\%$

$Al_2O_3=15.9\%$

$CaO=6.4\%$

$MgO=4.7\%$

$SiO_2$ is called quartz

$Al_2O_3$ is called corundum

$CaO$ is called calcium oxide or quick lime

$MgO$ is called magnesium oxide or magnesia

You might be interested in

On Earth a package weighs 19.6 newtons. What is the mass of this package on Earth?

kondor19780726 [428]

g = 19.6 N/2.2 kg. g = 8.9 m/s2. 7.

4 0

2 years ago

A medical class is hearing a lecture on vision. The doctor asks them what happens when the eye produces too much fluid, causing

Charra [1.4K]

Answer:

The doctor is discussing an Ocular Hypertension disease.

Explanation:

If we have a small space with a defined volume like in this case an eye, when we fill this space with a liquid, the liquid will occupy the whole volume available, and when it is much liquid or fluid, and the volume of the eye can not expand it will start to generate an internal pressure. This higher pressure is called Hypertension.

3 0

2 years ago

in sample of elemental bromine, 55% or the atoms are Br-79, and the remainder are Br-81. if this sample is typical of naturally

Gwar [14]

Answer:

The average atomic mass of bromine is 79.9 amu.

Explanation:

Given data:

Percentage of Br⁷⁹ = 55%

Percentage of Br⁸¹ = 45%

Average atomic mass of bromine = ?

Formula:

Average atomic mass = [mass of isotope× its abundance] + [mass of isotope× its abundance] +...[ ] / 100

Now we will put the values in formula.

Average atomic mass = [55 × 79] + [81 ×45] / 100

Average atomic mass = 4345 + 3645 / 100

Average atomic mass = 7990 / 100

Average atomic mass = 79.9 amu

The average atomic mass of bromine is 79.9 amu.

3 0

2 years ago

Valproic acid, used to treat seizures and bipolar disorder, is composed of C, H, and O. A 0.165-g sample is combusted to produce

sergeinik [125]

Answer:

The empirical formula is = $C_4H_8O$

The formula of Valproic acid = $C_8H_{16}O_2$

Explanation:

Mass of water obtained = 0.166 g

Molar mass of water = 18 g/mol

Moles of $H_2O$ = 0.166 g /18 g/mol = 0.00922 moles

2 moles of hydrogen atoms are present in 1 mole of water. So,

Moles of H = 2 x 0.00922 = 0.01844 moles

Molar mass of H atom = 1.008 g/mol

Mass of H in molecule = 0.01844 x 1.008 = 0.018588 g

Mass of carbon dioxide obtained = 0.403 g

Molar mass of carbon dioxide = 44.01 g/mol

Moles of $CO_2$ = 0.403 g /44.01 g/mol = 0.009157 moles

1 mole of carbon atoms are present in 1 mole of carbon dioxide. So,

Moles of C = 0.009157 moles

Molar mass of C atom = 12.0107 g/mol

Mass of C in molecule = 0.009157 x 12.0107 = 0.11 g

Given that the Valproic acid only contains hydrogen, oxygen and carbon. So,

Mass of O in the sample = Total mass - Mass of C - Mass of H

Mass of the sample = 0.165 g

Mass of O in sample = 0.165 - 0.11 - 0.018588 = 0.036412 g

Molar mass of O = 15.999 g/mol

Moles of O = 0.036412 / 15.999 = 0.002276 moles

Taking the simplest ratio for H, O and C as:

0.01844 : 0.002276 : 0.009157

= 8 : 1 : 4

The empirical formula is = $C_4H_8O$

Molecular formulas is the actual number of atoms of each element in the compound while empirical formulas is the simplest or reduced ratio of the elements in the compound.

Thus,

Molecular mass = n × Empirical mass

Where, n is any positive number from 1, 2, 3...

Mass from the Empirical formula = 4×12 + 8×1 + 16= 72 g/mol

Molar mass = 144 g/mol

So,

Molecular mass = n × Empirical mass

144 = n × 72

⇒ n = 2

The formula of Valproic acid = $C_8H_{16}O_2$

7 0

2 years ago

suppose that during the icy hot lab that 65 kj of energy were transferred to 450 g of water at 20 C. What would have been the fi

balandron [24]

Answer:

The final temperature of water is 54.5 °C.

Explanation:

Given data:

Energy transferred = 65 Kj

Mass of water = 450 g

Initial temperature = T1 = 20 °C

Final temperature= T2 = ?

Solution:

First of all we will convert the heat in Kj to joule.

1 Kj = 1000 j

65× 1000 = 65000 j

specific heat of water is 4.186 J /g. °C

Formula:

q = m × c × ΔT

ΔT = T2 - T1

Now we will put the values in Formula.

65000 j = 450 g × 4.186 J /g. °C × (T2 - 20°C )

65000 j = 1883.7 j /°C × (T2 - 20°C )

65000 j/ 1883.7 j /°C = T2 - 20°C

34.51 °C = T2 - 20°C

34.51 °C + 20 °C = T2

T2 = 54.5 °C

5 0

2 years ago