Answer:
0.734 L or 734 mL
Step-by-step explanation:
We'll begin by calculating the number of mole of HCl in 20.0 mL of a 3.00 M solution of hydrochloric acid, HCl.
This is illustrated below:
Molarity of hcl = 3 M
Volume = 20 mL = 20/1000 = 0.02 L
Mole of HCl =..?
Molarity = mole /Volume
3 = mole /0.02
Cross multiply
Mole of HCl = 3 x 0.02
Mole of HCl = 0.06 mole.
Next, we shall determine the number of mole of Hydrogen gas, H2 produced from the reaction of 0.06 mole of HCl. This can obtain as follow:
Mg + 2HCl —> MgCl2 + H2
From the balanced equation above,
2 moles of HCl reacted to produce 1 mole H2.
Therefore, 0.06 mole of HCl will react to produce = (0.06 x 1)/2 = 0.03 mole
Therefore, 0.03 mole of H2 was produced.
Finally, we shall determine the volume of the balloon by calculating the volume of Hydrogen gas, H2 in the balloon.
The volume of H2 can be obtained by using the ideal gas equation as follow:
Pressure (P) = 1 atm
Temperature (T) = 25°C = 25°C + 273 = 298K
Number of mole (n) of H2 = 0.03 mole
Gas constant (R) = 0.0821 atm.L/Kmol
Volume (V) of H2 =?
PV = nRT
1 x V = 0.03 x 0.0821 x 298
V = 0.734 L = 734 mL.
Therefore, the volume of the balloon is 0.734 L or 734 mL