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when air is heated what happens to its density?

A ) It is increased because the molecules are moving together.
B ) It is increased because the molecules are moving apart.
C ) It is decreased because the molecules are moving together.
D ) It is decreased because the molecules are moving apart

Answer:

1.84

Explanation: just input the value into the formula pv=nrt

p*30=2*0.08206*337 then divide both sides by 30 and  get 1.84

Answer:

b) The total moles of each element present in the reactants and in the products.

Explanation:

Hello there!

In this case, since the law of conservation of mass is used to realize that the mass, atoms and molecules of all the species involved in a chemical reaction must be the same at both reactants and products, we can see that a and c stand for those that must be equal; thus, we infer that the moles can be different as they stand for the amount of substance which is related to the mass via molar masses. Therefore, the answer would be b) The total moles of each element present in the reactants and in the products.

Regards!

Answer:

78.14% Pb²⁺ and 21.86% of Cd²⁺

Explanation:

The first titration involves the reaction of both Pb²⁺ and Cd²⁺

In the second titration, as the buffer is HCN/NaCN, the Cd²⁺ precipitates as Cd(CN)₂ and the only ion that reacts is Pb²⁺

In the first titration:

Moles EDTA = Moles Pb²⁺ and Cd²⁺:

28.89mL = 0.02889L * (0.06950moles / L) = 2.008x10⁻³ moles in the aliquot. In the sample:

2.008x10⁻³ moles * (250.0mL / 50.0mL) =

0.01004 moles = Pb²⁺ + Cd²⁺ (1)

In the second titration:

19.07mL = 0.01907L * (0.06950mol / L) = 1.325x10⁻³ moles Pb²⁺ in the aliquot. In the sample:

1.325x10⁻³ moles Pb²⁺ * (250.0mL / 50.0mL) =

6.626x10⁻³ moles Pb²⁺

That means the moles of Cd²⁺ are:

0.01004 moles = Cd²⁺ + 6.626x10⁻³ moles Cd²⁺

3.413x10⁻³ moles Cd²⁺

The mass of each ion is:

Cd²⁺ -Molar mass: 112.411g/mol-:

3.413x10⁻³ moles Cd²⁺ * (112.411g / mol) =

0.384g of Cd²⁺

Pb²⁺ -Molar mass: 207.2g/mol-:

6.626x10⁻³ moles Pb²⁺ * (207.2g / mol) =

1.373g of Pb²⁺

The percent mass of each ion is:

1.373g Pb²⁺ / 1.757g = 78.14% Pb²⁺

And:

0.384g of Cd²⁺ / 1.757g * 100 = 21.86% of Cd²⁺

Explanation:

I think it is the first option

Answer:

1) They expand to completely fill their container.   :)

Explanation:

Answer:

pH = 2.25

Explanation:

pH is a measurement in chemistry defined as the -log [H₃O⁺]. Molarity [], is defined as the ratio between moles of solute (HCl) and the liters of solution

To solve this question we must find the molarity of the H₃O⁺ knowing: [HCl] = [H₃O⁺]

[HCl]:

0.0084moles / 1.500L

= 0.0056M = [HCl] = [H₃O⁺]

pH = -log [H₃O⁺] = -log [0.0056M]

A solution prepared by dissolving 0.0084 moles of HCl in 1500 mL of solution has a molar concentration of HCl of 5.6 × 10⁻³ M, a molar concentration of H₃O⁺ of 5.6 × 10⁻³ M and a pH of 2.3.

A solution is prepared by dissolving 0.0084 moles of HCl in 1500 mL of solution. The molarity of HCl is:

[tex][HCl] = \frac{0.0084mol}{1.5L} = 5.6 \times 10^{-3} M[/tex]

HCl is a strong acid according to the following equation.

HCl(aq) + H₂O(l) ⇒ Cl⁻(aq) + H₃O⁺(aq)

Thus, the concentration of H₃O⁺ will be equal to the initial concentration of HCl, 5.6 × 10⁻³ M.

Finally, we will calculate the pH of the solution using its definition.

[tex]pH = -log [H_3O^{+} ] = -log (5.6 \times 10^{-3} ) = 2.3[/tex]

A solution prepared by dissolving 0.0084 moles of HCl in 1500 mL of solution has a molar concentration of HCl of 5.6 × 10⁻³ M, a molar concentration of H₃O⁺ of 5.6 × 10⁻³ M and a pH of 2.3.

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Answer:

Ice melts into liquid water- endothermic

A process with a calculated positive q - endothermic

Wood burns in a fireplace - exothermic

A process with a calculated negative q - exothermic

Acid and base are mixed, making test tube feel hot - exothermic

Solid dissolves into solution, making ice pack feel cold - endothermic

Explanation:

An endothermic process is one in which heat is absorbed from the surroundings. The absorption of heat means that heat is removed from the surroundings hence the surroundings feel cool. When heat is absorbed, q is positive.

An exothermic process is one in which heat is released to the surroundings. The evolution of heat means that heat is released into the surroundings hence the surroundings feel hot . When heat is evolved, q is negative.

Answer:

This question is a bit vague. We're not told if 500ml is the volume of the solution and additional info is not given to calculate the volume of pbNo3 being added.

If you solve with 500ml as the volume of solution ... You'll have the answer below.

Molarity=moles of solutes/Volume of solvent(in litres)

moles of solute given=1.565moles

Volume = 500ml. There's 1000ml to a litre. Dividing by 1000ml to convert to Litres... You have 0.5L

Molarity = 1.565/0.5

=3.13M

Answer:

See Explanation

Explanation:

The presence of chloride ions in water can be established by adding dilute trioxonitrate V acid to a sample of the water in drops followed by aqueous silver trioxonitrate V.

If a white precipitate is formed, which is soluble in excess aqueous ammonia solution, then the presence of chloride ion in the water sample is ultimately confirmed.

Answer:

Rutherford passed beams of alpha particles through a thin gold foil to observe the atom and noted how the alpha particles scattered from the foil.

Observations of Rutherford's alpha ray scattering experiment:

1.Most of the α-particles passed straight through the gold foil without any deviation.

2. Some of the α-particles were deflected by the foil by some angles.

3.Interestingly one out of every 12,000 alpha particles appeared to rebound

Conclusion of Rutherford's scattering experiment:

1.Most of the space inside the atom is empty because most of the α-particles passed through the gold foil without getting deflected.

2. Very few particles were deflected from their path, indicating that the positive charge of the atom occupies very little space.

3. A very small fraction of α-particles were deflected by very large angles, indicating that all the positive charge and mass of the gold atom were concentrated in a very small volume within the atom.

Answer:

50 dm³

Explanation:

Assuming constant temperature, we can solve this problem using Boyle's law, which states:

Where in this case:

We input the data:

And solve for V₂:

Thus the answer is 50.0 dm³ H₂.

Answer:

0.75 L

Explanation:

V1/T1 = V2/T2

V1 = 0.520 L

T1 = 18 C = 291 K (make sure to convert to Kelvin by adding 273 to the Celsius temperature)

V2 = ?

T2 = 422 K

Solve the equation for V2

V2 = V1T2/T1

V2 = (0.520 L)(422 K) / (291 K) = 0.754 L ≈ 0.75 L (since it says to only give two significant figures)

Answer:

[tex]m_{solute}=0.05g[/tex]

Explanation:

Hello there!

In this case, according to the equation for the calculation of the parts per million:

[tex]ppm=\frac{m_{solute}}{m_{solution}} *1x10^6[/tex]

It is possible to solve for the mass of KI (solute) as shown below:

[tex]m_{solute}=\frac{ppm*m_{solution}}{1x10^6}[/tex]

Thus, we plug in to obtain:

[tex]m_{solute}=\frac{25*2,000g}{1x10^6} \\\\m_{solute}=0.05g[/tex]

Best regards!

Answer:

2 mol

Explanation:

There are 4 mols of O per one sulfate so since there is only one sulfate you simply times 4 by .5 to get the number of mol

Answer:

Explanation:

Around 439 million years ago, 86% of life on Earth was wiped out. Scientists believe two major events resulted in this extinction: glaciation and falling sea levels. Some theories suggest that the Earth was covered in such a vast quantity of plants that they removed too much carbon dioxide from the air which drastically reduced the temperature. Falling sea levels were possibly a result of the Appalachian mountain range forming. The majority of the animal life lived in the ocean. Trilobites, brachiopods, and graptolites died off in large numbers but interestingly, this did not lead to any major species changes during the next era.

Answer:

The food chain starts as prey to a preditor and then when the preditor dies the prey eat the preditor

Explanation:

Just that

Explanation:

21.0 g of potassium reacts with 62.5 g of barium nitride, what mass of potassium nitride will be produced

Answer:

The Coriolis effect

Explanation:

The Coriolis effect is the effect that makes tornados, water spouts, and are often seen in storms. They make water curve and rotate as well as the wind And current.

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Answer: True

I hope this helped!

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Answer:

true

Explanation:

Answer:

800 g

Explanation:

We can express the decay of I-37 using the formula:

We input the data:

And solve for Initial Mass:

Meaning that out 800 grams of I-37, only 25 will remain after 40.35 days.

Answer:

40.1 g

Explanation:

The balanced equation is:

First we convert 86.5 g of calcium chlorate into moles, using its molar mass:

Then we convert Ca(ClO₃)₂ moles into O₂ moles, using the stoichiometric coefficients of the balanced reaction:

Finally we convert O₂ moles into grams:

Upon studying the orbit of Uranus more closely, astronomers realized its orbit was being affected by the presence of another very large mass - so the hunt was on for another large planet. He sent his prediction to the Astronomer Royal, Sir George Airy, who passed it on to an 'observer'.

más inteligente o gracias por favor :)) <33 / brainliest or a thank you please :)) <33

The position of Uranus was predicted by determining the position of a larger mass ( Neptune ) exerting a gravitational push on Uranus

Uranus is the 7th planet in the galaxy it was initially  discovered with the aid of a telescope by an astronomer whom initially thought it was a star.

The position of Uranus was predicted when an astronomer ( John Couch Adams ) and his colleague predicted the gravitational effect on Uranus from another larger mass ( Neptune ). they discovered the position of the larger mass affecting the orbit of Uranus and the position of this larger mass ( Neptune ) was used to predict the position of Uranus in the galaxy.

Hence we can conclude that the position of Uranus was predicted by determining the position of a larger mass ( Neptune ) exerting a gravitational push on Uranus

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Answer: As the temperature of a molecular system increases, the kinetic energy of molecules also increase. Also as the temperature of a molecular system decreases, the kinetic energy of the molecules will also decrease.

Explanation:

James Clerk Maxwell developed the kinetic-molecular theory (KMT) of gases. In this theoey, five assumptions concerning an ideal gas was made. One of the them was that," the average kinetic energy of the gas molecules is proportional to the temperature of the gas". This simply means that a s the temperature of a molecular system increases, the kinetic energy of molecules also increase. Also as the temperature of a molecular system decreases, the kinetic energy of the molecules will also decrease.

Also another scientist known as Rudolf Clausius incorporated energy into the kinetic theory. He proposed that heat is a form of energy that affects the temperature of matter by changing the motion of molecules in matter.

Heat is defined as the flow of energy which is caused by difference in temperature.

In conclusion, when the temperature of a system is increased, the collision of the molecules with one another and the walls of their container increases as more molecules gain more heat energy at higher temperature. While as the temperature of the system decreases, the collision of the molecules will also decrease as molecules lose heat energy at lower temperature.

Answer:

Temperature increases the average kinetic energy of the atoms as well as molecules increases because when the temperature increases the collision between the atom and molecules increases and particles may collide with one another.

because it may associate with the thermal energy when thermal energy increases because of the motion of the gas particle and may initiate the kinetic energy of the gas.

when the temperature goes increasing the movement of the particle is at a very high rate, especially in gas and then solids, and especially this must be increased when the endothermic reaction is involved this must proceed such a reaction that the temperature results in to increase in the average kinetic energy.

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Answer:  4 atoms is the answer. I hope it helped you.

Explanation:

Answer:

Explanation:

your not so smart