All categories

3 years ago

A small sphere of initial volume V is filled with n moles of helium at initial pressure and temperature P and T.

Chemistry

1 answer:

Gwar [14]3 years ago

7 0

Complete Question:

A small sphere of initial volume V is filled with n moles of helium at initial pressure and temperature and T. Which of the following statements is true?

a) The volume decreases to V/2, and the pressure increases to 4P when the temperature is T/2

b) n/2 moles of gas are removed, the volume is decreased to V/2, and the pressure decreases to P/4 with a drop in temperature of T/2

c) n moles of gas are added, the total sample is heated to 2T, and the pressure drops to P/2 when the volume increases to 8V

d) The amount of gas is doubled to 2n, the pressure is doubled to 2P, and the volume is doubled to 2V, with a corresponding temperature drop to T/2

Answer:

Explanation:

Let's consider the helium as an ideal gas, so it can be studied by the ideal gas law, which states:

PV = nRT

Where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant and T is the temperature. Because R is constant:

PV/nT = R. Thus the initial state must be equal to the final state.

So, let's check the statements:

a) Let's indicate the final state as P₂, V₂, n₂ and T₂. So, if T₂ = T/2:

PV/nT = P₂V₂/n₂T₂

PV/nT = P₂V₂/n₂(T/2)

PV/nT = 2P₂V₂/n₂T

So, if V₂ = V/2 and P₂ = 4P:

PV/nT = 2*(V/2 * 4P)/n2T

PV/nT = 4VP/n2T

Which is not correct!

b) Now, if T₂ = T/2:

PV/nT = 2P₂V₂/n₂T

If n/2 is removes, n₂ = n/2. And, V₂ = V/2 and P₂ = P/4:

PV/nT = 2*(V/2 * P/4)/(n/2)*T

PV/nT = 4*(V/2 *P/4)/nT

PV/nT = PV/2nT

Which is not corret!

c) Now, if V₂ = 8V:

PV/nT = P₂*8V/n₂T₂

And n₂ = n +n = 2n, T₂ = 2T and P₂ = P/2:

PV/nT = (P/2)*8V/2n*2T

PV/nT = 8*(PV)/2*2n*2T

PV/nT = 8*(PV)/8*(nT)

PV/nT = PV/nT

So, it's correct!

d) Now, T₂ = T/2, n₂ = 2n, P₂ = 2P, and V₂ = 2V:

PV/nT = 2P*2V/2n*(T/2)

PV/nT = 4PV/nT

Which is not correct!

You might be interested in

A sample of sodium reacts completely with 0.497 kg of chlorine, forming 819 g of sodium chloride. What mass of sodium reacted?

dolphi86 [110]

Answer:

$819 \: g = 819 \times {10}^{ - 3} \: kg = 0.819 \: kg \\ 0.819 \: kg - 0.497 \: kg \\ = 0.322 \: kg$

4 0

3 years ago

Which of these electron transitions correspond to absorption of energy and which to emission?

Keith_Richards [23]

The electron transitions representing absorption of energy are:

(a) n = 2 to n = 4

(d) n = 3 to n = 4

and those which represents emissions of energy are:

(b) n = 3 to n = 1

An electron emits energy when it jumps from a higher energy level to a lower energy level transitions.

An electron absorbs energy to jump from a lower energy level to a higher energy level transitions.

(a) n = 2 to n = 4

Here, the initial level (2) is lower than the final level (4).

Hence energy is absorbed.

(b) n = 3 to n = 1

Here, the initial level (3) is higher than the final level (1).

Hence energy is released.

Here, the initial level (5) is higher than the final level (2).

Hence energy is released.

(d) n = 3 to n = 4

Here, the initial level (3) is lower than the final level (4).

Hence energy is absorbed.

The question is incomplete. Find the complete question here:

Which of these electron transitions correspond to absorption of energy and which to emission?

(a) n = 2 to n = 4

(b) n = 3 to n = 1

(d) n = 3 to n = 4

Learn more about electron transitions at brainly.com/question/2079874

#SPJ4

4 0

2 years ago

Which change shows a tenfold increase in the concentration of H+ ions? Which change shows a tenfold increase in the concentratio

nadya68 [22]

(D): pH 2- pH 1 good luck

7 0

4 years ago

How do you know if your hypothesis is supported by your results or not?

vivado [14]

Answer:

Your hypothesis is an educated guess of what the end results of an experiment will be, using what you already know about your experiment you are going to conduct. So when you receive your final results, if your hypothesis is correct, or even somewhat correct then you know that it is supported by your results. For example, if I were to conduct the Coca-Cola and Mentos experiment, I could make a hypothesis that the Coca-Cola will have a bigger eruption when I add more than one Mento to the bottle due to a higher amount of a chemical with the addition of each mento. When I receive my results that the eruption was bigger each time, I know that my results supported my hypothesis.

Explanation:

-Hope this helped

5 0

1 year ago

Sulfur undergoes combustion to yield sulfur trioxide by the following reaction equation:

12345 [234]

Answer:

Therefore, the amount of heat produced by the reaction of 42.8 g S = (-5.2965 × 10²) kJ = (-5.2965 × 10⁵) J

Explanation:

Given reaction: 2S + 3O₂ → 2 SO₃

Given: The enthalpy of reaction: ΔH = - 792 kJ

Given mass of S: w₂ = 42.8 g, Molar mass of S: m = 32 g/mol