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3 years ago

The mass of 1.63x10^21 silicon atoms is how many grams

1 answer:

6 0

Lyle stirs 5.0 grams of salt into a beaker of water. He then adds 15.0 grams of pure iodine to the mixture. If the total mass of the new mixture is 225 grams, what is the mass of the water

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The experiment above is repeated, but instead of extracting once with 6 mL the extraction is done three times with 2 mL of dichl

nevsk [136]

Complete Question

A student is extracting caffeine from water with dichloromethane. The K value is 4.6. If the student starts with a total of 40 mg of caffeine in 2 mL of water and extracts once with 6 mL of dichloromethane

The experiment above is repeated, but instead of extracting once with 6 mL the extraction is done three times with 2 mL of dichloromethane each time. How much caffeine will be in each dichloromethane extract?

Answer:

The mass of caffeine extracted is $P = 39.8 \ mg$

Explanation:

From the question above we are told that

The K value is $K = 4.6$

The mass of the caffeine is $m = 40 mg$

The volume of water is $V = 2 mL$

The volume of caffeine is $v_c = 2 mL$

The number of times the extraction was done is n = 3

Generally the mass of caffeine that will be extracted is

$P = m * [\frac{V}{K * v_c + V} ]^3$

substituting values

$P = 40 * [\frac{2}{4.6 * 2 + 2} ]^3$

$P = 39.8 \ mg$

6 0

3 years ago

How do you balance hgo ?

Marina CMI [18]

What are you asking? Id love to help but cant without proper information

8 0

3 years ago

13. A mixture of MgCO3 and MgCO3.3H2O has a mass of 3.883 g. After heating to drive off all the water the mass is 2.927 g. What

rjkz [21]

Answer:

63.05% of MgCO3.3H2O by mass

Explanation:

of MgCO3.3H2O in the mixture?

The difference in masses after heating the mixture = Mass of water. With the mass of water we can find its moles and the moles and mass of MgCO3.3H2O to find the mass percent as follows:

Mass water:

3.883g - 2.927g = 0.956g water

Moles water -18.01g/mol-

0.956g water * (1mol/18.01g) = 0.05308 moles H2O.

Moles MgCO3.3H2O:

0.05308 moles H2O * (1mol MgCO3.3H2O / 3mol H2O) =

0.01769 moles MgCO3.3H2O

Mass MgCO3.3H2O -Molar mass: 138.3597g/mol-

0.01769 moles MgCO3.3H2O * (138.3597g/mol) = 2.448g MgCO3.3H2O

Mass percent:

2.448g MgCO3.3H2O / 3.883g Mixture * 100 =

6 0

2 years ago

Suppose you have 15.0 ml of zinc. What volume of aluminum would have the same mass as the zinc?

Black_prince [1.1K]

Answer:

$\large \boxed{\text{41.2 cm}^{3}}$

Explanation:

1. Mass of zinc

The density of zinc is 7.14 g/cm³

D = m/V

$\begin{array}{rcl}7.14 & = & \dfrac{m}{15.0}\\\\m & = & 7.14 \times 15.0\\& = & \text{107.1 g}\\\end{array}\\$

2. Volume of aluminium

The density of aluminium is 2.60/cm³.

$\begin{array}{rcl}2.60 & = & \dfrac{107.1}{V}\\\\2.60V & = & 107.1\\V& = &\dfrac{107.1}{2.60}\\\\& = &\textbf{41.2cm}^{\mathbf{3}}\\\end{array}\\\large \boxed{\textbf{41.2 cm}^{\mathbf{3}}}\text{ of aluminium have the same mass as 15.0 cm$^{3}$ of zinc.}$

5 0

3 years ago

What is the symbol of an ion with 16 protons, 18 neutrons, and 18 electrons? what is the symbol for an ion that has 16 pro-tons,

Goshia [24]

When we go to periodic table, Sulfur is an element that has 16 protons and 16 electrons.

when there is 18 electrons, with number of two electrons more than protons. This makes it an ion and the ion has a -2 charge.

So when there is16 protons, 18 neutrons, and 18 electrons the symbol is S⁻².

The neutrons have no charge but they add only mass to the elements. So when there is 16 neutrons, it doesn't change the symbol of ion.

3 0

3 years ago