Question

The mass of zinc was 0.125 grams, the barometric pressure recorded was 758 mm Hg the temperature was 20 degrees Celsius.Assuming all the zinc reacted,find the volume of gas (H2) collected. The equation is attached!

Answer 1

To solve this question, we use the Clapeyron equation. The Clapeyron equation is a mathematical expression that relates quantities such as pressure (P), volume (V), temperature (T) and the number of particles (n) that make up an ideal gas.

PV = nRT

we have

P = 758 mmHg

V = ???

n = we can find it using the mass of zinc

R = 0.082 atm.L/mol.K

T = 20 °C

So first let's transform 758 mmHg into atm.

1 atm --- 760 mmHg

x atm --- 758 mmHg

x = 0.997369 atm

Now let's find n, using the following formula: moles = mass/molar mass

molar mass of Zn is 65.38 g/mol

moles = 0.125/65.38

moles = 1.9 x 10^-3 moles

Let's transform 20 °C into kelvin

Tk = Tc + 273

Tk = 20 + 273

Tk = 293 K

Now let's replace the values on the formula:

0.997369 x V = 1.9 x 10^-3 x 0.082 x 293

V = 0.0459/0.997369

V = 0.0461 L

Answer: V = 0.0461 L