please help me do it dont worry the answers are their just put them in theright place

Answer: the answer is “C”

Explanation:

Took the T E S T

Answer:

X5Y2

Explanation:

% composition of X = 52.2%

% composition of Y = (100 - 52.2) = 47.8%

This means that there are 52.2g of X and 47.8g of Y in the compound

To calculate the empirical formula of the compound, we first convert the gram value to mole value by dividing by their molar masses.

X = 52.2g/42.3g/mol = 1.234mol

Y = 47.8g/96.7g/mol = 0.494mol

Next, we divide each mole value by the smallest value (0.494mol)

X = 1.234mol ÷ 0.494mol = 2.49

Y = 0.494mol ÷ 0.494mol = 1

We multiply each value by 2

X = 2.49 × 2 = 4.98

Y = 1 × 2 = 2

The simple ratio of X:Y is 5:2, hence, their empirical formula is X5Y2.

Answer:

c

Explanation:

h

Answer:

Explanation:

A titration in general is used to determine the concentration of something with a solution of known solution. For acid, a base solution of known concentration is added slowly. The end-point is determined by using a pH indicator. When the acid is neutralized at the end, note the amount of base solution used and the strength of acid can be calculated.

Note that the quantity of base solution utilised and the acid strength can be estimated after the acid has been neutralised.

Titration is a method of chemical analysis where the quantity of a sample's constituents is established by adding a precisely measured amount of something else with which the component that is wanted will react in a specific, known proportion.

A burette, which is essentially a long, graded measurement tube with a stopper and a tube for injection at its bottom end, is used to gradually administer a standard solution of titrating reagent, and titrant, to a specified concentration. When the point of equal value is achieved, the addition is terminated. Note that the quantity of base solution utilised and the acid strength can be estimated after the acid has been neutralised.

Therefore, note that the quantity of base solution utilised and the acid strength can be estimated after the acid has been neutralised.

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Answer:

893 moles

Explanation:

An ideal gas at STP occupies 22.4 liters. Calculating Oxygen as if it were an ideal gas there are . 893 moles of Oxygen in 20.0 liters.

Answer:

I think both

Explanation:

Answer:

Modal means the one that occurs most often (averages: mode). In maths, the mode is one of the most common ways to describe a set of data. ... The modal class is, therefore, the group with the highest frequency.

Answer:

Modal means the one that occurs most often (averages: mode). In maths, the mode is one of the most common ways to describe a set of data. ... The modal class is, therefore, the group with the highest frequency. For example: if you counted the number of pencils in different pencil cases and you decided to group them.

Explanation:

தமிழன் ❤

Answer:

Certain breeds of fish will often clean bigger fish. The cleaner fish gets food, the bigger fish gets a cleaning.

I'm not too sure.

Good luck! <3

Answer:

T₂ = 478.93 K

Explanation:

Given that,

Initial pressure, P₁ = 178 kPa

Initial temperature, T₁ = 37°C = 310 K

Final pressure, P₂ = 275 kPa

We need to find the new temp of the air in the tire, assuming the volume is constant. We know that,

[tex]\dfrac{P_1}{T_1}=\dfrac{P_2}{T_2}\\\\T_2=\dfrac{P_2T_1}{P_1}\\\\T_2=\dfrac{275\times 310}{178}\\\\T_2=478.93 K[/tex]

So, the new temperature is equal to 478.93 K.

Answer:

There would be 3 temperature changes and 2 phase transitions

Explanation:

The temperature of the material would first increase from T0 to Tm (its melting point)- This is one temperature change.

It would the change from solid to liquid at its melting point Tm.- This is one phase transition.

Its temperature would then increase from its melting point Tm to its boiling point Tv -This is another temperature change.

It would then change from liquid to gas at its boiling point Tv - This is another phase transition.

Finally, its temperature would then increase from its boiling point to T(f) - This is the third temperature change.

So, there would be 3 temperature changes and 2 phase transitions

Answer:

hi

Explanation:

because

Answer:

Explanation:

The name is of the compound is 3,3,4,4-tetramethylhexane.

Answer:

Photosynthesis

Explanation:

Photosynthesis uses energy from light to convert water and carbon dioxide molecules into glucose (sugar molecule) and oxygen. The oxygen is released, or “exhaled”, from leaves while the energy contained within glucose molecules is used throughout the plant for growth, flower formation, and fruit development.

Answer: I think it is ‘Genetically diverse’

Explanation:

Answer:PV=nRT ideal gas law

P presdure

V volume

n number of moles of gas

R gas constant

T temperature

Explanation: V=nRT/P

2liters=nR300k/P

divide by 2 for the equation

1liters=nR150k/P

with nR remaining constant

Answer:

0.852 mol

Explanation:

First we convert 4.00 g of helium (He) into moles, using its molar mass:

4.00 g ÷ 2 g/mol = 2 mol He

To answer this problem we can use Avogadro's law, which states that at constant pressure and temperature:

V₁n₂=V₂n₁

Where:

We input the data:

And solve for n₂:

Answer:

Products

Explanation:

Answer:

Explanation:

Bird courtship and mating dances include many unique ways to attract mates. Learn about their courtship behaviors and why they matter. ... When birders recognize courting birds, they can be sure to avoid disturbing ... the charming songs used to woo partners can help distinguish species so birds are sure ...

Answer:

The correct answer is -

1. D. mold

2. A. Cast

3. F. trace fossil

4. C. original material fossils

5. B. fossil record.

Explanation:

Mold is the impression of an organism in a rock that occurs due to the complete dissolving of the organism and only an impression left in sedimentary rocks.

The cast is a fossil copy of an organism in a rock that takes place when water-containing minerals fill the molds and creates a three-dimension copy of the fossil.

Trace fossils are the fossils that are preserved in such a manner that records of biological activity stored only instead of remains of plants or animals.

Storing originals animals or parts of the remaining such as tissue of an organism in natural form is known as original-material fossils.

Fossil records are the fossils ever found or discovered on the earth.

Answer:

[tex]\boxed {\boxed {\sf 3. \ H-H}}[/tex]

Explanation:

To determine the polarity of a bond, we use the electronegativities of the individual atoms. The greater the difference, the more polar the bond.

1. H-Br

3.0-2.2=0.8

2. H-F

4.0-2.2=1.8

3. H-H

2.2-2.2=0.0

4. H-O

3.4-2.2=1.2

As we can see, the lowest difference is in hydrogen hydrogen at 0.0. You may also recognize that because they are 2 atoms of the same element, the electronegativity is the same for both, so it will equal 0. Since the electronegativity is 0, this is a nonpolar bond.

The mass of water present in the solution is 21.5 g.

Concentration refers to the amount of solute in a solution. There are various ways of expressing concentration such as;

We have the following information;

Percent concentration = 35.0 %

mass of solute = 40.0 g

Mass of water = ?

So;

35 = x/40 + x × 100/1

35 = 100x/40 + x

35(40 + x) = 100x

1400 + 35x = 100x

1400 = 100x - 35x

1400 = 65x

x = 1400/65

x = 21.5 g

Hence the mass of water is 21.5 g.

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Answer:

12.3 kJ

Explanation:

For a given substance, the molar heat of fusion basically tells you one thing from two perspectives

how much heat is needed in order to melt one mole of that substance at its melting point

how much heat must be removed in order to freeze one mole of that substance at its freezing point

It is very important to realize that the molar enthalpy of fusion will carry a positive sign when you're dealing with melting and a negative sign when you're dealing with freezing.

The water is formed from oxygen gas and...hydrogen gas, I'm assuming? It would have been nice for the question to have been a bit more explicit (not blaming you, of course).

Assuming that's the case, our chemical reaction would be:

2H₂(g) + O₂(g) → 2H₂O(l).

We are told that 1 mol of a gas has a volume of 24.0 dm³ at RTP. We can use this relation to determine the number of moles of O₂ gas that reacts given its initial volume, 33.5 dm³.

33.5 dm³ O₂(g)/24.0 dm³/mol = 1.396 mol O₂(g).

Since we are not given any information about H₂(g), or any other reactant for that matter, I am assuming that the O₂(g) is the limiting reactant. According to the equation, the stoichiometric ratio between O₂ and H₂O is 1:2. That is, for every one mole of O₂ that is consumed, two moles of H₂O are formed (i.e., the number of moles of H₂O formed is double the number moles of O₂).

Since 1.396 moles of O₂ reacts, 2(1.396) = 2.792 moles of H₂O are produced. To convert moles of water to grams, we multiply the number of moles of H₂O by the molar mass of H₂O:

(2.792 moles H₂O)(18.015 g/mol) = 50.3 g H₂O.

So, approximately 50.3 grams of water are formed from 33.5 dm³ of oxygen gas at RTP.

Answer:

Because the sun is low on the horizon, sunlight passes through more air at sunset and sunrise than during the day, when the sun is higher in the sky. More atmosphere means more molecules to scatter the violet and blue light away from your eyes.

Answer:

There are 0.311 moles of  gas in the tank

Explanation:

Complete question

A 4.00g sample of gas is found to exert a pressure of 1.71 atm when confined in 3.60L container at a temperature of 241 K. Find the number of moles of the gas

Solution

As we know

[tex]PV = nRT[/tex]

where P is the pressure of the gas in atm

V is the volume in liters

n is the number of moles

R is the gas constant = 0.08206 L·atm/K·mol

and T is the temperature in Kelvin

Substituting the given values in above equation, we get -

[tex]1.71 * 3.60 = n * 0.08206 * 241\\n = 0.311[/tex]

There are 0.311 moles of  gas in the tank

Answer:

e

Explanation:

and e

Answer:

Explanation:

Maintaining a healthy, perennial plant cover.

Mulching.

Planting a cover crop – such as winter rye in vegetable gardens. ...

Placing crushed stone, wood chips, and other similar materials in heavily used areas where vegetation is hard to establish and maintain.???

Answer:

1.14 M

Explanation:

First divide the mass of NaOH by the molar mass of NaOH. Then divide by the volume to get molarity.

34.2 g / 39.997 g/mol = 0.855 mol NaOH

0.855 mol NaOH / 0.750 L = 1.14 M NaOH