Question

(iii) Calculate the volume of carbon dioxide
that would be produced (measured at room
temperature and pressure (rtp)) if 12.5g of
zinc carbonate were heated strongly.

Answer 1

Answer:

4.6 g of sodium reacts completely with excess water:

2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g)

Calculate the volume of hydrogen produced. (Ar of Na = 23, molar volume = 24 dm3)

Step 1 - Calculate the amount of sodium

Amount in mol =

Amount in mol =

Amount of sodium = 0.20 mol

Step 2 - Find the amount of hydrogen

From the balanced equation, the mole ratio Na:H2 is 2:1

Therefore 0.20 mol of Na produces = 0.10 mol of H2

Step 3 - Calculate the volume of hydrogen

Volume = amount in mol × molar volume

Volume = 0.10 × 24

= 2.4 dm3