In a reaction 6.56g of Zinc reacted with excess dilute Hydrochloric acid Calculate the volume of hydrogen evolved at STP
divide the mass of Zn by its molar mass to find the number of moles
each mole of Zn results in one mole of H2
a mole of gas at STP occupies 22.4 L
Well, let's get this calculation rolling. But first, let me tell you a joke to lighten the mood.
Why did the scarecrow win an award?
Because he was outstanding in his field!
Now, back to your question. To calculate the volume of hydrogen evolved, we need to use the ideal gas law. At STP (Standard Temperature and Pressure), the conditions are a temperature of 0 degrees Celsius (273.15K) and a pressure of 1 atmosphere (atm).
First, we need to calculate the number of moles of zinc reacted. The molar mass of zinc (Zn) is approximately 65.38 g/mol. So, we have:
moles of Zn = mass of Zn / molar mass of Zn
moles of Zn = 6.56g / 65.38 g/mol
Next, based on the balanced chemical equation, we know that one mole of zinc reacts with 2 moles of hydrochloric acid (HCl) to produce 1 mole of hydrogen gas (H2).
So, moles of H2 = moles of Zn / 2
Finally, we can use the ideal gas law equation: PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant (0.0821 L·atm/(mol·K)), and T is the temperature in Kelvin.
Using the ideal gas law, we can rearrange the equation to solve for V:
V = (nRT) / P
Substituting the values we have, we get:
V = (moles of H2 x R x T) / P
V = (moles of Zn / 2) x R x T / P
Using the values for STP (T = 273.15K, P = 1 atm) and the ideal gas constant (R = 0.0821 L·atm/(mol·K)), you should be able to calculate the volume of hydrogen evolved.
To calculate the volume of hydrogen evolved at STP, we need to use the concept of stoichiometry. The balanced chemical equation for the reaction between zinc and hydrochloric acid is:
Zn + 2HCl → ZnCl2 + H2
From the balanced equation, we can see that 1 mole of zinc reacts with 2 moles of hydrochloric acid to produce 1 mole of hydrogen gas.
First, we need to calculate the number of moles of zinc present in the reaction:
Molar mass of zinc (Zn) = 65.38 g/mol
Mass of zinc (given) = 6.56 g
Number of moles of zinc = mass / molar mass
= 6.56 g / 65.38 g/mol
≈ 0.1 mol
Since the reaction is given to have an excess of hydrochloric acid, all the zinc will react. Thus, 0.1 moles of zinc will produce 0.1 moles of hydrogen gas.
Now, we can use the ideal gas law to calculate the volume of hydrogen gas at STP (standard temperature and pressure). STP conditions are defined as a temperature of 273.15 K and a pressure of 1 atmosphere (atm).
Using the ideal gas law: PV = nRT
P = 1 atm (pressure at STP)
V = volume of gas (to be determined)
n = number of moles of gas (0.1 moles)
R = ideal gas constant (0.0821 L·atm/mol·K)
T = temperature (273.15 K)
Rearranging the ideal gas law equation gives:
V = (n * R * T) / P
= (0.1 mol * 0.0821 L·atm/mol·K * 273.15 K) / 1 atm
≈ 2.24 L
Therefore, the volume of hydrogen gas evolved at STP is approximately 2.24 liters.
To calculate the volume of hydrogen evolved at STP, you first need to determine the number of moles of zinc that reacted. Then you can use the stoichiometry of the reaction to determine the number of moles of hydrogen produced. Finally, you can use the ideal gas law to convert the number of moles of hydrogen to volume at STP.
Let's start by finding the number of moles of zinc that reacted. The molar mass of zinc (Zn) is approximately 65.38 g/mol. Given that you have 6.56 g of zinc, you can calculate the number of moles by dividing the mass by the molar mass:
moles of Zn = mass of Zn / molar mass of Zn
moles of Zn = 6.56 g / 65.38 g/mol
moles of Zn = 0.10 mol
Next, we need to determine the stoichiometry of the reaction to find the number of moles of hydrogen produced. The balanced chemical equation for the reaction between zinc and hydrochloric acid is:
Zn + 2HCl → ZnCl2 + H2
From the balanced equation, we can see that one mole of zinc reacts with two moles of hydrochloric acid to produce one mole of hydrogen.
moles of H2 = 0.10 mol (moles of Zn) * (1 mol H2 / 1 mol Zn)
moles of H2 = 0.10 mol
Now we can use the ideal gas law to convert the number of moles of hydrogen to volume at STP. The ideal gas law equation is:
PV = nRT
Where:
P = pressure (in this case, at STP, the pressure is 1 atm)
V = volume of gas
n = number of moles
R = ideal gas constant (0.0821 L·atm/(mol·K))
T = temperature (at STP, the temperature is 273 K)
To solve for V (volume), we rearrange the equation:
V = (nRT) / P
Substituting in the values we have:
V = (0.10 mol) * (0.0821 L·atm/(mol·K)) * (273 K) / (1 atm)
V ≈ 2.24 L
Therefore, approximately 2.24 liters of hydrogen gas are evolved at STP.