What is the law of multiple proportions?
A. The proportion of elements to compounds is constant.
B. All elements are found in equal proportions in nature.
C. Different compounds may contain the same elements but may have different ratios of those elements.
D. All compounds contain the same elements in the same proportions.

Answer:

1. Vacuole

2. chloroplast

3. Nucleus

4. Plasma membrane - cell membrane

5. Vacuole (same as #1 ?) could be vesicle

Explanation:

Answer:

Classify each of the following as either macroscopic, microscopic or particulate:

a. a red blood cell.

b. a sugar molecule.

c. baking powder.

Explanation:

a. A red blood cell is a microscopic particle.

It can be viewed under a microscope.

b. A sugar molecule is also a microscopic substance.

It can be viewed under a microscope.

c. Baking powder is macroscopic substance.

Answer:

14

73%

Explanation:

The mean Number of years worked :

. (sum of service years) / employees in the

(8+13+15+3+13+28+4+12+4+26+29+3+10+3+17+13+15+15+23+13+12+1+14+14+17+16+7+27+18+24) /

(417 / 30)

= 13.9 years

= 14 years

The percentage of employees who have worked for atleast 10 years :

Number of employees with service years ≥ 10 years = 22 employees

Total number of employees

Percentage (%) = (22 / 30= * 100% = 0.7333 * 100% = 73.33% = 73%

Explanation:

here is the answer. Feel free to ask for more chem help

Answer:

104.8 g

Explanation:

From the question given above, the following data were obtained:

Initial temperature of copper (T꜀) = 275.1 °C

Mass of water (Mᵥᵥ) = 272 g

Initial temperature of water (Tᵥᵥ) = 21 °C

Equilibrium temperature (Tₑ) = 29.7 °C

Mass of copper (M꜀) =?

NOTE:

Specific heat capacity of copper (C꜀) = 0.385 J/gºC

Specific heat capacity of water (Cᵥᵥ) = 4.184 J/gºC

Finally, we shall determine the mass of the copper in the sample. This can be obtained as follow:

Heat loss by copper = Heat gained by water

M꜀C꜀(T꜀ – Tₑ) = MᵥᵥCᵥᵥ(Tₑ – Tᵥᵥ)

M꜀ × 0.385 (275.1 – 29.7) = 272 × 4.184(29.7 – 21)

M꜀ × 0.385 × 245.4 = 1138.048 × 8.7

M꜀ × 94.479 = 9901.0176

Divide both side by 94.479

M꜀ = 9901.0176 / 94.479

M꜀ = 104.8 g

Thus, the mass of the copper in the sample is 104.8 g

Answer:

pH = -log[H+]

Where [H+] = Hydrogen ion concentration

In this case,

[H+] = 1 × 10^(-2) = 10^(-2)

log{10^(-2)} = -2

-log{10^(-2)} = -(-2) = 2

pH = -log{10^(-2)} = 2

and hi.!!!

Answer:

0.1

Explanation:

Hydrogen ion concentration can be calculated using the formula [H+] = 10^-pH

pH can be concentrated using ph = -log[H+]

let's calculate the initial pH before anything was added: pH = -log(1) = 0

it increased by 1 so the final pH is 1.

Now we'll find the [H+] of a solution with a pH of 1:

concentration = 10^(-1) = 0.1

Answer:

The correct option is A

Explanation:

Some amino acids, called glucogenic amino acids, when catabolized convert there carbon backbones to tricarboxylic acid (TCA) cycle intermediates. These intermediates can be subsequently metabolized into carbon dioxide and water with the release of ATP or the formation of glucose (known as gluconeogenesis.

All amino acids (with the exception of leucine and lysine) are glucogenic and can thus generate the carbon backbones required for gluconeogenesis. Thus, the correct option is a.

Answer:

pH=8.676

Explanation:

Given:

0.75 M [tex]NH_{3}[/tex]

0.20 M [tex]NH_{4}[/tex]

The objective is to calculate the pH of the buffer using the kb for [tex]NH_3[/tex]

Formula used:

[tex]pOH=pka+log\frac{[salt]}{[base]}\\[/tex]

pH=14-pOH

Solution:

On substituting salt=0.75 and base=0.20 in the formula

[tex]pOH=-log(1.77*10^{-5})+log\frac{0.75}{0.20}\\ =4.75+0.5740\\ =5.324[/tex]

pH=14-pOH

On substituting the pOH value in the above expression,

pH=14-5.324

Therefore,

pH=8.676

Answer:

Yes because same topic are long

Answer:

False

Explanation:

An object with a density greater than 1.00g/mL (greater than the density of water) will sink. An object with a density less than the density of water, will float.

If the water has a density of 1.00 g/mL. If you put an object that has a density of 0.79 g/mL into water, it will sink to the bottom, this statement is false.

The density of an actual content is its mass per unit volume. The most common symbol for density is d, but the Latin letter D can also be used.

Three of an object's most fundamental properties are mass, volume, and density. Mass describes how heavy something is, volume describes its size, and density is defined as mass divided by volume.

The density of something is a measure of how heavy it is in relation to its size. When an artifact is more dense than water, it plunges; when an object is less dense than water, it floats.

Density is a property of a substance that is independent of the amount of substance.

As in the given scenario, water is having density 1 g/mL and object in having density less then it so it will float on water.

Thus, the given statement is false as the material will not sink, rather it will float on water.

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Answer:

1. Its formation requires very strong updrafts = a. Hail

2. Its formation requires falling through a layer of above-freezing air = d. Freezing Rain

3. Precipitation from cumuliform clouds is typically of this nature = c. Shower

4. Precipitation from stratus clouds is typically of this nature = Drizzle

Explanation:

Hail formation requires very strong updrafts, these updrafts are the upward moving air created in a thunderstorm. This period of noticeable thunderstorms creates hails.

Freezing rain requires the presence of warm air, it requires falling through a layer of above-freezing air to the colder air below to produce an ice coating on anything it drops on.

Showers are produced by cumuliform clouds which look like cotton balls. Since cumuliform clouds precipitate too, these clouds can have fluctuating rain in a day in the form of showers.

Drizzle which raises low visibility is considered a type of liquid precipitation since it also falls from a cloud. Drizzle which is obviously smaller in diameter when compared to that of raindrops, however, is common with stratus clouds.

Answer:

0.518 g

Explanation:

Step 1: Write the balanced equation

3 CaCl₂ + 2 H₃PO₄ ⇒ Ca₃(PO₄)₂ + 6 HCl

Step 2: Calculate the moles corresponding to 0.555 g of CaCl₂

The molar mass of CaCl₂ is 110.98 g/mol.

0.555 g × 1 mol/110.98 g = 5.00 × 10⁻³ mol

Step 3: Calculate the moles of Ca₃(PO₄)₂ produced

5.00 × 10⁻³ mol CaCl₂ × 1 mol Ca₃(PO₄)₂/3 mol CaCl₂ = 1.67 × 10⁻³ mol Ca₃(PO₄)₂

Step 4: Calculate the mass corresponding to 1.67 × 10⁻³ moles of Ca₃(PO₄)₂

The molar mass of Ca₃(PO₄)₂ is 310.18 g/mol.

1.67 × 10⁻³ mol × 310.18 g/mol = 0.518 g

Answer:

e−(Ea/RT): the fraction of the molecules present in a gas which have energies equal to or in excess of activation energy at a particular temperature

Answer:

D. Temperature and activation energy is the correct answer

Explanation:

^_^

Answer:

The hot water dissolves the flavor and color components.

Explanation:

Caffeine can be extracted from the tea leaves into hot water because the hot water dissolves the flavor and color components away from the solid vegetable. This is an example of a solid-liquid extraction. We can extracted the aqueous solution and isolated the crude caffeine by converting the components of caffeine into their calcium salts which are insoluble in water. Then the caffeine can be extracted from the water by using methylene chloride.

Explanation:

here is the answer to your question.

Answer:

B

Explanation:

Spontaneous in chemical reactions means without any external input.

Occurring without added energy. Hence, option B is correct.

A spontaneous reaction is a reaction that supports the formation of products under the conditions under which the reaction is happening.

Spontaneous Reaction- a reaction that favours the formation of products at the conditions under which the reaction is occurring.

A non-spontaneous reaction can be made spontaneous if it is inside a controlled environment, this is what happens in nuclear power plants that create atomic fusion and fission in chambers that are controlled to control different particles to create nuclear active rays.

Hence, option B is correct.

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Answer:

It is equal to the total mass of the products.

Explanation:

Hope this helps :)

Answer:

Ni

Explanation:

An active metal is a highly reactive metal. Active metals are found high up in the activity series.

Active metals react with other metals that are lower than them in the activity thereby displacing the lower metals from a solution of their salts. This is what may have happened in the other two reactions.

Ni is the most active metal listed in the question since it can react a compounds with Pb(NO3)2(aq) to liberate Pb metal.

Answer: There are [tex]1.23 \times 10^{22}[/tex] atoms present in 37.1 mg of tantalum.

Explanation:

Given: Mass of single tantalum atom = [tex]3.01 \times 10^{-22} g[/tex]

Mass of tantalum atoms = 37.1 mg (1 mg = 0.001 g) = 0.0371 g

Therefore, number of tantalum atoms present in 0.0371 grams is calculated as follows.

[tex]No. of atoms = \frac{0.0371 g}{3.01 \times 10^{-22}}\\= 1.23 \times 10^{20}[/tex]

Thus, we can conclude that there are [tex]1.23 \times 10^{22}[/tex] atoms present in 37.1 mg of tantalum.

There are [tex]1.23\times 10^{20}[/tex] atoms of tantalum in 37.1 mg of tantalum.

Explanation:

Given:

Mass of single atom of tantalum =[tex]3.01\times 10^{-22} g[/tex]

To find:

The number of atoms of tantalum in 37.1 milligrams.

Solution:

Mass of tantalum = 37.1 mg

[tex]1 mg = 0.001 g\\37.1 mg=37.1\times 0.001 g=0.0371 g[/tex]

The number of atoms in 0.0371 grams of tantalum = N

Mass of a single atom of tantalum = [tex]3.01\times 10^{-22} g[/tex]

Then a mass of N atoms of tantalum will be:

[tex]0.0371 g=N\times 3.01\times 10^{-22} g\\N=\frac{0.0371 g}{ 3.01\times 10^{-22} g}\\=1.23\times 10^{20}[/tex]

There are [tex]1.23\times 10^{20}[/tex] atoms of tantalum in 37.1 mg of tantalum.

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Answer:

The most important difference between the two is that butter is derived from dairy and is rich in saturated fats, whereas margarine is made from plant oils. ... If the margarine contains partially hydrogenated oils, it will contain trans fat, even if the label claims that it has 0 g.

Explanation:

(⌒_⌒;)

Answer:

The correct answer is "[tex]4.991\times 10^{-45} \ kg.m^2[/tex]".

Explanation:

According to the question,

[tex]R_{C-Cl} = 177 \ pm[/tex]

or,

         [tex]=1.77\times 10^{-10} \ m[/tex]

[tex]\alpha = 107^{\circ}[/tex]

[tex]m_{Cl}=34.97 \ m.u[/tex]

or,

      [tex]=34.97\times 1.66\times 10^{-27}[/tex]

      [tex]=5.807\times 10^{-26} \ kg[/tex]

The moment of inertia around the rotational axis will be:

⇒  [tex]I=3\times m_{Cl}\times (R_{C-Cl})^2 \ Sin^2 \alpha[/tex]

By putting the values, we get

       [tex]=3\times 5.807\times 10^{-26}\times (1.77\times 10^{-10})^2 \ Sin^2 (107)[/tex]

       [tex]=3\times 5.807\times 10^{-26}\times (1.77\times 10^{-10})^2\times 0.91452[/tex]

       [tex]=4.991\times 10^{-45} \ kg.m^2[/tex]

Answer:

heating of gases depends not only on the temperature difference, but also on the process as well as the amount of gas present.

Explanation:

The work done when a gas is heated does not only depends on the initial and final states of the gas but also on the process used to achieve the change of state of the gas.

Several processes can be applied in changing the state of a gas such as; adiabatic process, isobaric process, isochoric process and isothermal process.

Hence, the heating of a gas, depends not only on the temperature difference, as well as the amount of gas present according to the ideal gas laws but also on the process used to achieve the change of state.

Answer: The reaction, [tex]2C(s) + MnO_{2}(s) \rightarrow Mn(s) + 2CO(g)[/tex] is a single-displacement reaction.

Explanation:

A chemical reaction in which one element of a compound is replaced by another element participating in the reaction.

For example, [tex]2C(s) + MnO_{2}(s) \rightarrow Mn(s) + 2CO(g)[/tex]

Here, the element manganese is replaced by carbon atom. As only one element gets replaced so, it is a single-displacement reaction.

Thus, we can conclude that [tex]2C(s) + MnO_{2}(s) \rightarrow Mn(s) + 2CO(g)[/tex] is a single-displacement reaction.

Answer:

Hope it is helpful to you

Answer:

Explanation:

First we convert the given masses into moles, using the compounds' respective molar mass:

Then we multiply each amount by Avogadro's number, to calculate the number of molecules:

Answer:

All energy is made by the sun because without the sun there would be no humans to produce other energy

Explanation:

We use many different forms of energy here on earth, but here’s the thing: almost all of them originate with the sun, not just light and heat (thermal) energy! The law of conservation of energy says that energy can’t be created or destroyed, but can change its form. And that’s what happens with energy from the sun—it changes into lots of different forms:

Plants convert light energy from the sun into chemical energy (food) by the process of photosynthesis. Animals eat plants and use that same chemical energy for all their activities.

Heat energy from the sun causes changing weather patterns that produce wind. Wind turbines then convert wind power into electrical energy.

Hydroelectricity is electrical energy produced from moving water, and water flows because heat energy from the sun causes evaporation that keeps water moving through the water cycle.

Right now, much human activity uses energy from fossil fuels such as coal, oil, and natural gas. These energy sources are created over very long periods of time from decayed and fossilized living matter (animals and plants), and the energy in that living matter originally came from the sun through photosynthesis.

solar panel shows what is the ultimate source of energy

Answer:

0.111 g

Explanation:

1 g = 1000 mg

Doctor ordered the following concentration of Claforan:

C = 1 g/100 mL x 1000 mg/1 g = 10 mg/mL

If we add 2 g iof Claforan, we obtain:

2 g Claforn ---- 180 mg/mL Claforan

To reach a concentration equal to C (10 mg/mL), we need:

10 mg/mL Claforan x 2 g Claforn/(180 mg/mL Claforan) = 0.111 g Claforn

Therefore, we have to add 0,111 g (111 mg) of Claforn to the bag of 100 ml D5W to obtain the ordered concentration of 10 mg/mL Claforan.  

Answer:

0.796 M

Explanation:

Step 1: Given data

Gravimetric concentration (Cg): 4.78 g%g

Density of the solution (ρ): 1.00 g/mL

Step 2: Calculate the volumetric concentration of the solution (Cv)

We will use the following expression.

Cv = Cg × ρ

Cv = 4.78 g%g × 1.00 g/mL = 4.78 g%mL

Step 3: Calculate the molarity of the solution (M)

The volumetric concentration is 4.78 g%mL, that is, there are 4.78 g of acetic acid per 100 mL of solution. We can calculate the molarity using the following expression.

M = mass solute / molar mass solute × liters of solution

M = 4.78 g / 60.05 g/mol × 0.1 L = 0.796 M

Pyruvate Kinase

Pyruvate Kinase performs a substrate level phosphorylation on ADP to generate an ATP and pyruvate, the final product of glycolysis.

PK dificiency is transmitted in an autosomal recessive disorder in which both alleles must contain the mutated gene, PK-LR.

Hope it helps you! ＼(^ᴥ^)／

Answer:

delocalised electrons

Explanation:

they are called delocalised electrons because that can move freely in the molecule