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Answer:

605.6mg of quinine

Explanation:

Based on Lambert-Beer's law, the intensity of an optical measurement is directely proportional to its concentration.

Unknown concentration gives a reading of 327

100 ppm gives 180 of intensity

The concentration of the diluted quinine tablet is:

327 * (100ppm / 180) = 181.67 ppm. The final dilution

The concentration of the first diluted solution is:

181.67 ppm * (100.0mL / 15mL) = 1211ppm

ppm could be defined as mass of solute (In this case of quinine) in mg per liter of solution. That is:

1211mg / L

As the tablet was diluted to 500mL = 0.5L, the mass of the quinine is:

0.5L * (1211mg / L) =

Answer:

[tex]V_2=9.20L[/tex]

Explanation:

Hello there!

In this case, according to the given STP (standard pressure and temperature), it is possible for us to realize that the equation to use here is the Avogadro's law as a directly proportional relationship between moles and volume:

[tex]\frac{V_2}{n_2}= \frac{V_1}{n_1}[/tex]

In such a way, given the initial volume and both initial and final moles, we can easily compute the final volume as shown below:

[tex]V_2= \frac{V_1n_2}{n_1} \\\\V_2=\frac{5.36L*6.0mol}{3.5mol}\\\\V_2=9.20L[/tex]

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Answer:A, can be caused by hurricanes

Explanation: got 100 on assignment

Answer:

a

Explanation:

Answer:

moles Na = 0.1114 g / 22.9898 g/mol=0.004846

moles Tc = 0.4562g /98.9063 g/mol=0.004612

mass O = 0.8961 - ( 0.1114 + 0.4562)=03285 g

moles O = 0.3285 g/ 15.999 g/mol=0.02053

divide by the smallest

0.02053/ 0.004612 =4.45 => O

0.004846/ 0.004612 = 1.0 => Tc

to get whole numbers multiply by 2

Na2Tc2O 9

Explanation:

Hope it right hope it helps

Answer:

a. pH = 2.04

b. pH = 3.85

c. pH = 8.06

d. pH = 11.56

Explanation:

The nitrous acid is a weak acid (Ka = 5.6x10⁻⁴) that reacts with NaOH as follows:

HNO₂ + NaOH → NaNO₂(aq) + H₂O(l)

a. At the beginning there is just a solution of 0.12M HNO₂. As Ka is:

Ka = [H⁺] [NO₂⁻] / [HNO₂]

Where [H⁺] and [NO₂⁻] ions comes from the same equilibrium ([H⁺] = [NO₂⁻] = X):

5.6x10⁻⁴ = X² / 0.15M

8.4x10⁻⁵ = X²

X = [H⁺] = 9.165x10⁻³M

As pH = -log [H⁺]

b. At this point we have HNO₂ and NaNO₂ (The weak acid and the conjugate base), a buffer. The pH of a buffer is obtained using H-H equation:

pH = pKa + log [NaNO₂] / [HNO₂]

Where pH is the pH of the buffer,

pKa is -log Ka = 3.25

And [NaNO₂] [HNO₂] could be taken as the moles of each compound.

The initial moles of HNO₂ are:

0.100L * (0.15mol / L) = 0.015moles

The moles of base added are:

0.0800L * (0.15mol / L) = 0.012moles

The moles of base added = Moles of NaNO₂ produced = 0.012moles.

And the moles of HNO₂ that remains are:

0.015moles - 0.012moles = 0.003moles

Replacing in H-H equation:

pH = 3.25 + log [0.012moles] / [0.003moles]

c. At equivalence point all HNO2 reacts producing NaNO₂. The volume added of NaOH must be 100mL. That means the concentration of the NaNO₂ is:

0.15M / 2 = 0.075M

The NaNO₂ is in equilibrium with water as follows:

NaNO₂(aq) + H₂O(l) ⇄ HNO₂(aq) + OH⁻(aq) + Na⁺

The equilibrium constant, kb, is:

Kb = Kw/Ka = 1x10⁻¹⁴ / 5.6x10⁻⁴ = 1.79x10⁻¹¹ = [OH⁻] [HNO₂] / [NaNO₂]

Where [OH⁻] = [HNO₂] = x

[NaNO₂] = 0.075M

1.79x10⁻¹¹ = [X] [X] / [0.075M]

1.34x10⁻¹² = X²

X = 1.16x10⁻⁶M = [OH⁻]

pOH = -log [OH-] = 5.94

pH = 14-pOH

d. At this point, 5mL of NaOH are added in excess, the moles are:

5mL = 5x10⁻³L * (0.15mol / L) =7.5x10⁻⁴moles NaOH

In 100mL + 105mL = 205mL = 0.205L. [NaOH] = 7.5x10⁻⁴moles NaOH / 0.205L =

3.66x10⁻³M = [OH⁻]

pOH = 2.44

pH = 14 - pOH

Answer:

There are 1.8021⋅1024 molecules of CH4 in 48 grams of CH4 .

Explanation:

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Answer:

a. Aqueous

Explanation:

Took the test

Explanation:

The Earth has different compositional and mechanical layers. Compositional layers are determined by their components, while mechanical layers are determined by their physical properties.

The Earth has different compositional and mechanical layers. Compositional layers are determined by their components, while mechanical layers are determined by their physical properties.Information about the compositional layers

The Earth has different compositional and mechanical layers. Compositional layers are determined by their components, while mechanical layers are determined by their physical properties.Information about the compositional layersLayer Definition Depth

The Earth has different compositional and mechanical layers. Compositional layers are determined by their components, while mechanical layers are determined by their physical properties.Information about the compositional layersLayer Definition DepthCrust :The outermost solid layer of a rocky planet or natural satellite. Chemically distinct from the underlying mantle. 0-100km silicates

The Earth has different compositional and mechanical layers. Compositional layers are determined by their components, while mechanical layers are determined by their physical properties.Information about the compositional layersLayer Definition DepthCrust :The outermost solid layer of a rocky planet or natural satellite. Chemically distinct from the underlying mantle. 0-100km silicatesMantle :A layer of the Earth (or any planet large enough to support internal stratification) between the crust and the outer core. It is chemically distinct from the crust and the outer core. The mantle is not liquid. It is, however, ductile, or plastic, which means that on very long time scales and under pressure it can flow. The mantle is mainly composed of aluminum and silicates. 100-2900km iron and magnesium silicates

The Earth has different compositional and mechanical layers. Compositional layers are determined by their components, while mechanical layers are determined by their physical properties.Information about the compositional layersLayer Definition DepthCrust :The outermost solid layer of a rocky planet or natural satellite. Chemically distinct from the underlying mantle. 0-100km silicatesMantle :A layer of the Earth (or any planet large enough to support internal stratification) between the crust and the outer core. It is chemically distinct from the crust and the outer core. The mantle is not liquid. It is, however, ductile, or plastic, which means that on very long time scales and under pressure it can flow. The mantle is mainly composed of aluminum and silicates. 100-2900km iron and magnesium silicatesCore: The innermost layers of the Earth. The Earth has an outer core (liquid) and an inner core (solid). They are not chemically distinct from each other, but they are chemically distinct from the mantle. The core is mainly composed of nickel and iron. 2900-6370km meta

Answer:

pH= 4; pOH= 10

Explanation:

HCl is a strong acid and therefore dissociates completely in a solution of water via HCl + H2O --> Cl- + H3O+.

Because it is a strong acid, [HCl] = [H3O+].

[HCl]= [H3O+]= (0.005 mol)/(50L)= 1.0 x 10^-4

pH= -log[H3O+]

pH= -log(1.0 x 10^-4)= 4

pH + pOH = 14

4 + pOH = 14

pOH= 10

Answer:

A five-sided shape is called a pentagon.

Explanation:

Answered by NONE other than the ONE & ONLY #QUEEN herself aka #DRIPPQUEENMO!!!

Hope this helped!!!

Answer:

a pentagon

Explanation:

I remember that a pentagon has 5 sides

Answer:

10.5 g

Explanation:

Step 1: Given data

Step 2: Calculate the moles of solute (n)

Molarity is equal to the moles of solute divided by the liters of solution.

M = n/V

n = M × V

n = 0.243 mol/L × 0.580 L = 0.141 mol

Step 3: Calculate the mass corresponding to 0.141 moles of KCl

The molar mass of KCl is 74.55 g/mol.

0.141 mol × 74.55 g/mol = 10.5 g

Explanation:

2,4-DNP is negative: aldehyde and ketone absent

Chromic acid is negative: alcohol absent.

KMnO4 test negative: alkene absent

The only positive result is for Fe(OH)2.

Nitro group-containing compounds react with ferrous hydroxide to give amine and ferric hydroxide red ppt. Hence given compound contains the nitro group (-NO2).

Answer: I believe the answer is A, heat moves from warmer objects to cooler objects. I know for sure it isn’t C or D though so A

The heat is transferred from one object to another as heat moves from warmer objects to cooler objects. The correct option is A.

There are three ways to transfer heat. They are conduction, convection, and radiation. Heat travels from one body to another body. If the temperature of two objects is different, then the heat travels from higher temperature to lower temperature.

Conduction is the transfer of energy when two objects ate in contact with each other. Convection is a transfer between object and environment. Radiation is when transferred by emission of electromagnetic radiation.

Thus, the correct option is A. Heat moves from warmer objects to cooler objects.

Learn more about the transfer of heat, here:

https://brainly.com/question/13433948

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Answer:

Show a picture

Explanation:

1.267 x 10 ^ 24 is the total number of atoms

Answer:

40 and 10

Explanation:

40 plus 10 is 50 40 minus 10 is 30

Answer:

40 and 10

Explanation:

Answer:

I₂CL₆

Explanation:

Answer12C1

Explanation:

Answer:

In humans, there are two major processes used to convert glucose into energy. cellular respiration or aerobic respiration is one of these processes that take place in presence of oxygen that converts glucose into CO2.

The other process is lactic acid fermentation occurs in muscles in case of depletion of oxygen which converts glucose into lactic acid.

The third process is alcoholic fermentation does not take place in humans and occurs in yeast and some bacteria where they produce ethanol.

Humans cannot use alcoholic fermentation in their own body ferment as there is no genetic information in us to do so as it has encoded in yeast and bacteria.

Answer:

Chemical energy

Explanation:

By the use of electrons and protons from water

Answer:

chemical energy

Explanation:

Photosynthesis is the process by which organisms that contain the pigment chlorophyll convert light energy into chemical energy which can be stored in the molecular bonds of organic molecules (e.g., sugars). Photosynthesis powers almost all trophic chains and food webs on the Earth.

Answer:

A decrease in temperature decreases the number of collisions between molecules . The reaction rate will  decrease

Explanation:

Answer:

4.92 grams of sodium phosphate (Na₃PO₄) are required to make 125 milliliters of a 0.240 M.

Explanation:

Molarity is a measure of concentration that indicates the number of moles of solute that are dissolved in a given volume.

The molarity of a solution is calculated by dividing the moles of the solute by the volume of the solution:

[tex]Molarity=\frac{number of moles}{volume}[/tex]

Molarity is expressed in units [tex]\frac{moles}{liter}[/tex].

In this case:

Replacing in the definition of molarity:

[tex]0.240 M=\frac{number of moles}{0.125 L}[/tex]

Solving:

number of moles= 0.240 M*0.125 L

number of moles= 0.03 moles

Being the molar mass of sodium phosphate 164 g/mole, that is, the mass of one mole of the compound, you can calculate the mass of 0.03 moles using the following rule of three: if 1 mole of the compound has 164 grams, 0.03 moles contains how much mass?

[tex]mass=\frac{0.03 moles*164 grams}{1 mole}[/tex]

mass= 4.92 grams

4.92 grams of sodium phosphate (Na₃PO₄) are required to make 125 milliliters of a 0.240 M.

Answer:

dfgh

Explanation:

Explanation:

Carbon has the ability to form long chains of carbon atoms as well as ringed compounds by continuously bonding to itself. This covalent bonds may be single, double, or triple. Carbon forms covalent bonds easily with other elements, especially hydrogen, oxygen, nitrogen, halogens, and a variety of nonmetals.

Answer:

[tex]\color{Blue}\huge\boxed{Answer} [/tex]

Water moves through the hydrosphere in a cycle. Water collects in clouds, then falls to Earth in the form of rain or snow. This water collects in rivers, lakes and oceans. Then it evaporates into the atmosphere to start the cycle all over again.

Answer:

B.

Our pupils contract and expand depending on the amount of light at any given time in order to avoid being blinded and to see better in the darkness.

Answer:

Molarity=Moles of solute/volume of solution in Litres

Simply imputing your values

you have

0.75/65

0.0115M.