1. What is the Kelvin temperature of a system in which 4.50 mol of a gas occupy 0.250 L at 4.15 atm?
2. In the lab, students generated and collected hydrogen gas according to the following equations:
Zn + H2SO4---> H2 + ZnSO4
a) How many mL of hydrogen gas at STP were generated from 52.7 g of zinc metal?
b) If 525 mL of hydrogen gas at STP were needed, how many moles of H2SO4 would be required?
Use PV = nRT for #1.
The next two are stoichiometry problems. Just follow the steps in the link below.
http://www.jiskha.com/science/chemistry/stoichiometry.html
1. To find the Kelvin temperature, we can use the Ideal Gas Law equation: PV = nRT.
Given:
- Volume (V) = 0.250 L
- Pressure (P) = 4.15 atm
- Number of moles (n) = 4.50 mol
R is the ideal gas constant, which is 0.0821 L·atm/(mol·K).
To find the Kelvin temperature (T), we need to rearrange the formula: T = PV / (nR).
Substituting the known values:
T = (4.15 atm) * (0.250 L) / (4.50 mol * 0.0821 L·atm/(mol·K))
By performing the calculation, we find:
T ≈ 240 K
Therefore, the Kelvin temperature of the system is approximately 240 K.
2. a) To determine the volume of hydrogen gas at STP generated from a given mass of zinc, we need to use stoichiometry and the ideal gas law.
The balanced equation gives us the stoichiometric ratio:
1 mol of Zn reacts to produce 1 mol of H2.
First, we need to convert the mass of zinc to moles using its molar mass. The molar mass of zinc (Zn) is approximately 65.38 g/mol.
Number of moles of zinc (n) = 52.7 g / 65.38 g/mol
To determine the volume of hydrogen gas at STP, we can use the ratio: 1 mol of H2 = 22.4 L (at STP).
Volume of hydrogen gas (V) = (number of moles of zinc) * (22.4 L/mol)
By substituting the given values and performing the calculations, we can find the volume of hydrogen gas at STP generated from 52.7 g of zinc metal.
b) To find the number of moles of H2SO4 required to produce a given volume of hydrogen gas at STP, we use the same stoichiometric ratio as in part (a).
The stoichiometric ratio from the balanced equation is:
1 mol of H2SO4 reacts to produce 1 mol of H2.
So, the number of moles of H2SO4 (n) is equal to the desired volume of hydrogen gas (V) in liters, as 1 mol of H2SO4 produces 1 mol of H2, which is 22.4 L at STP.
Therefore, the number of moles of H2SO4 required is equal to the given volume of hydrogen gas at STP, which is 525 mL.
The volume of hydrogen gas (V) in liters is given as 525 mL = 525/1000 L.
So, the number of moles of H2SO4 required is 525/1000 mol.
By using stoichiometry, we can determine the number of moles of H2SO4 required to generate 525 mL of hydrogen gas at STP from the given information.