Answer:
V = 0.0859dm³
Explanation:
Hydroiodic acid, HI, reacts with potassium, K, to produce potassium iodide, KI, and hydrogen, as follows:
2HI + 2K → 2KI + H₂(g)
To solve this question we have to find the moles of hydrogen produced knowing that 2 moles of K produce 1 mole of H₂. With the moles of hydrogen we can find the volume of hydrogen assuming there are STP conditions:
<em>Moles K -Molar mass: 39.0983g/mol-</em>
3g * (1mol / 39.0983g) = 0.0767 moles of K
<em>Moles H₂:</em>
0.0767 moles of K * (1mol H₂ / 2mol K) = 0.03836 moles H₂
Using: PV = nRT; V = nRT / P
<em>Where V is volume in dm³,</em>
<em>n are moles of gas: 0.03836 moles,</em>
<em>R is gas constant = 0.082atm*dm³/molK</em>
<em>T is absolute temperature = 273.15K at STP</em>
<em>and P is pressure = 1atm</em>
The volume of the gas is:
V = 0.03836mol*0.082atm*dm³/molK*273.15K / 1atm
<h3>V = 0.0859dm³</h3>
