Gas Laws

Step 1: Understanding Gay-Lussac's Law:
According to Gay-Lussac's Law of Combining Volumes, gases react in a simple whole-number ratio by volume, provided temperature and pressure remain constant.
Step 2: Analyzing the Stoichiometry:
From the balanced equation: [ underbrace1 text vol._C_3H_8 + 5 text vol. O_2 underbrace3 text vol._CO_2 + 4 text vol. H_2O ] This means 1 litre of propane produces 3 litres of carbon dioxide.
Step 3: Calculating for 5 Litres:
Volume of CO_2 = 5 text litres (propane) times 3 = 15 text litres.
Step 4: Final Answer:
The volume of CO_2 produced is 15 litres.

(a) Moles of Zinc:
Moles of Zn = Given Mass / Atomic Mass = 32.5 / 65 = 0.5 moles

(b) Mass of Nitric Acid:
From the equation, 1 mole of Zn reacts with 4 moles of HNO3.
Therefore, 0.5 moles of Zn will react with:
0.5 × 4 = 2 moles of HNO3
Molecular weight of HNO3 = 1 + 14 + (16 × 3) = 63 g/mol.
Mass = Moles × Molar Mass = 2 × 63 = 126 g

(c) Volume of NO2 at STP:
From the equation, 1 mole of Zn produces 2 moles of NO2.
Therefore, 0.5 moles of Zn will produce:
0.5 × 2 = 1 mole of NO2
Since 1 mole of any gas occupies 22.4 L at STP:
Volume = 22.4 litres