What volume of hydrogen gas (at STP) will be liberated by the reaction of excess Zn on 50 mL dilute H2so4 of specific gravity = 2 (g/ml) and w/w percentage 49% ?
Answers
The volume of hydrogen liberated is 6.4 L.
Answer:
What volume of hydrogen gas (at STP) will be liberated by the reaction of excess Zn on 50 mL dilute H2so4 of specific gravity = 2 (g/ml) and w/w percentage 49% ?
The volume of hydrogen liberated is 6.4L.
Step 1. Calculate the mass of H2SO4
Mass of H2SO4=50mL solution×1.3g solution
1mL solution×40 g H2SO4
100g solution =26.0 g H2SO4
Step 2. Calculate the moles of H2SO4
Moles of H2SO4 = 26.0g H2SO4× 1mol
H2SO498.08g H2SO4 =0.265 mol H2SO4
Step 3. Write the balanced equation for the reaction
Zn + H2SO4→H2+ZnSO4
Step 4. Calculate the moles of H2
Moles of H2=0.265 mol H
2SO4×1 mol H
21mol H
2SO4 =0.265 mol H2
Step 5. Calculate the volume of hydrogen
We can use the Ideal Gas Law to calculate the volume:
¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯
apV= nR Ta
−−−−−−−−−−−−−−−
We can rearrange the Ideal Gas Law to get
V= nRTp
Since NTP is 20 °C and 1 atm, we have
n=0.265 mol
R=0.082 06 L⋅ atm ⋅K -1 mol-1T
=(20 + 273.15) K = 293.15 Kp=1 atm
V=0.265mol×0.082 06 L⋅atm
⋅
K-1 mol
-1×293.15K
1atm=6.4 L