Answer:
1) The limiting reactant is N₂ because it is present with the lower no. of moles than H₂.
2) The amount (in grams) of excess reactant H₂ = 4.39 g.
Explanation:
- Firstly, we should write the balanced equation of the reaction:
<em>N₂ + 3H₂ → 2NH₃.</em>
<em>1) To determine the limiting reactant of the reaction:</em>
- From the stichiometry of the balanced equation, 1.0 mole of N₂ reacts with 3.0 moles of H₂ to produce 2.0 moles of NH₃.
- This means that <em>N₂ reacts with H₂ with a ratio of (1:3).</em>
- We need to calculate the no. of moles (n) of N₂ (5.23 g) and H₂ (5.52 g) using the relation:<em> n = mass / molar mass.</em>
The no. of moles of N₂ in (5.23 g) = mass / molar mass = (5.23 g) / (28.00 g/mol) = 0.1868 mol.
The no. of moles of H₂ (5.52 g) = mass / molar mass = (5.52 g) / (2.015 g/mol) = 2.74 mol.
- From the stichiometry, N₂ reacts with H₂ with a ratio of (1:3).
The ratio of the reactants of N₂ (5.23 g, 0.1868 mol) to H₂ (5.52 g, 2.74 mol) is (1:14.67).
∴ The limiting reactant is N₂ because it is present with the lower no. of moles than H₂.
0.1868 mol of N₂ react completely with 0.5604 mol of H₂ and the remaining of H₂ is in excess.
<em>2) To determine the amount (in grams) of excess reactant of the reaction:</em>
- As showed in the part 1, The limiting reactant is N₂ because it is present with the lower no. of moles than H₂.
- Also, 0.1868 mol of N₂ react completely with 0.5604 mol of H₂ and the remaining of H₂ is in excess.
- The no. of moles are in excess of H₂ = 2.74 mol - 0.5604 mol (reacted with N₂) = 2.1796 mol.
- ∴ The amount (in grams) of excess reactant H₂ = n (excess moles) x molar mass = (2.1796 mol)((2.015 g/mol) = 4.39 g.
Answer: Option (A) is the correct answer.
Explanation:
Rate of diffusion is defined as the total movement of molecules from a region of higher concentration to lower concentration.
The interaction between medium and the material is responsible for the rate of diffusion of a material or substance.
A small concentration gradient means small difference in the number of molecules taking part in a reaction. So, when there no large difference between the concentration then there won't be much difference in the rate of diffusion of a material.
Whereas a higher concentration of molecules will lead to more number of collisions due to which frequency of molecules increases. Therefore, rate of diffusion will also increase.
Small molecule size will also lead to increases in rate of diffusion. This is because according to Graham's law rate of diffusion is inversely proportional to molar mass of an element. Hence, smaller size molecule will have smaller mass. As a result, rate of diffusion will be more.
High temperature means more kinetic energy of molecules due to which more number of collisions will be there. Hence, rate of diffusion will also increase.
Thus, we can conclude that out of the given options a small concentration gradient is least likely to increase the rate of diffusion.
Zirconium cannot be broken down by a chemical change, because it is an element. The others are all molecules.
