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lawyer [7]
3 years ago
7

Umm care to help, please

Chemistry
2 answers:
marysya [2.9K]3 years ago
4 0

Answer:

17.5

Explanation:

Archy [21]3 years ago
3 0

20

Explanation:

Protons (the atomic number) and neutrons both contribute to the atomic mass.

If you therefore subtract the number of protons (19) from the atomic mass (39), you are left with the number of neutrons (=20).

hope this helped :)

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A sample of gas has a density of 0.53 g/L at 225 K and under a pressure of 108.8 kPa. Find the density of the gas at 345 K under
sukhopar [10]

Answer:

\rho _2=0.22g/L

Explanation:

Hello!

In this case, since we are considering an gas, which can be considered as idea, we can write the ideal gas equation in order to write it in terms of density rather than moles and volume:

PV=nRT\\\\PV=\frac{m}{MM} RT\\\\P*MM=\frac{m}{V} RT\\\\P*MM=\rho RT

Whereas MM is the molar mass of the gas. Now, since we can identify the initial and final states, we can cancel out R and MM since they remain the same:

\frac{P_1*MM}{P_2*MM} =\frac{\rho _1RT_1}{\rho _2RT_2} \\\\\frac{P_1}{P_2} =\frac{\rho _1T_1}{\rho _2T_2}

It means we can compute the final density as shown below:

\rho _2=\frac{\rho _1T_1P_2}{P_1T_2}

Now, we plug in to obtain:

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Regards!

8 0
3 years ago
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