Question

Please show all your work! :)

Answer 1

The answer to this problem is A!

Answer 2

A

Step-by-step explanation:

First, we're given that the atmospheric pressure is 744.8 mmHg. However, this includes the pressure of the Zinc and the pressure of the water; we only want the pressure of the water, so subtract its pressures (23.8 mmHg) from 744.8 mmHg: 744.8 - 23.8 = 721 mmHg.

Now, we can use the ideal gas law: PV = nRT.

- the pressure P is 721 mmHg

- the volume V is 7.80 L

- the moles n of Zinc is what we want to find in order to calculate the mass

- the gas constant R is 62.36 L mmHg / (mol K)

- the temperature T is 25.0°C, or 25.0 + 273 = 298 K

Plug all these in:

PV = nRT

(721 mmHg) * (7.80 L) = n * (62.36) * (298 K)

n ≈ 0.303 mol Zn

We need to convert this to grams, so use the molar mass of Zinc, which is 65.38 g/mol:

`0.303molZn*(65.38g)/(1mol) =19.8gZn`

Thus, the answer is A.