Hydrogen gas is produced when zinc reacts with sulfuric acid:

Zn(s)+H_2SO_4(aq)---ZnSO_4(aq)+H_2(g)

If 160 mL of wet H_2 is collected over water at 24 Celsius and a barometric pressure of 739 torr, how many grams of Zn have been consumed? (The vapor pressure of water is 22.38 torr.)

Use PV = nRT to solve for n = number of moles H2, then use stoichiometry (link supplied for a worked example) to calculate grams Zn used.

http://www.jiskha.com/science/chemistry/stoichiometry.html

To find the grams of Zn consumed, we first need to calculate the partial pressure of hydrogen gas (H2).

Step 1: Convert the collected volume of hydrogen gas to the pressure of H2.
Using Dalton's Law of Partial Pressure, the partial pressure of H2 is equal to the difference between the total pressure and the vapor pressure of water:
Partial pressure of H2 = Total pressure - Vapor pressure of water
Partial pressure of H2 = 739 torr - 22.38 torr
Partial pressure of H2 = 716.62 torr

Step 2: Convert the partial pressure of H2 to moles of H2.
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.

Rearranging the equation, we have:
n = PV / RT

Converting the units to the appropriate ones for the equation:
P = 716.62 torr (converted to atm: 1 atm = 760 torr)
V = 160 mL (converted to L: 1 L = 1000 mL)
R = 0.0821 L·atm/(mol·K)
T = 24°C (converted to Kelvin: T(K) = T(°C) + 273.15)

Plugging in the values, we get:
n = (716.62 torr / 760 torr) * (160 mL / 1000 mL) / (0.0821 L·atm/(mol·K) * (24°C + 273.15)
n ≈ 0.0156 mol

Step 3: Determine the molar ratio of Zn to H2.
From the balanced chemical equation, the stoichiometric ratio between Zn and H2 is 1:1. This means that 1 mole of Zn reacts to produce 1 mole of H2.

Step 4: Calculate the grams of Zn consumed.
Since the molar ratio is 1:1, the number of moles of Zn consumed is also 0.0156 mol.

The molar mass of Zn is 65.38 g/mol.

Therefore, the grams of Zn consumed is:
Mass of Zn = number of moles * molar mass
Mass of Zn = 0.0156 mol * 65.38 g/mol
Mass of Zn ≈ 1.019 g

So, approximately 1.019 grams of Zn have been consumed.

To determine the number of grams of Zn consumed, we need to use the ideal gas law equation:

PV = nRT

Where:
P is the total pressure (barometric pressure - vapor pressure of water)
V is the volume of the gas
n is the number of moles of gas
R is the ideal gas constant
T is the temperature in Kelvin

First, let's convert the given temperature from Celsius to Kelvin:
T = 24 Celsius + 273.15 = 297.15 K

Next, we need to calculate the total pressure by subtracting the vapor pressure of water from the barometric pressure:
P = 739 torr - 22.38 torr = 716.62 torr

Now, let's convert the volume of hydrogen gas to liters:
V = 160 mL = 160/1000 = 0.16 L

We can now rearrange the ideal gas law equation to solve for the number of moles of hydrogen gas:
n = PV/RT

Substituting the values we have:
n = (716.62 torr)(0.16 L) / [(0.0821 L·atm/(mol·K))(297.15 K)]

Now, simplify the equation by converting torr to atm and canceling units:
n = (716.62 atm)(0.16 L) / (0.0821 L·atm/(mol·K))(297.15 K)
n = 0.0743 mol

According to the balanced chemical equation, the stoichiometric ratio between Zn and H2 is 1:1. Therefore, the number of moles of Zn consumed is also 0.0743 mol.

To find the mass of Zn consumed, we need to use the molar mass of Zn, which is 65.38 g/mol. We can calculate the mass of Zn consumed using the formula:

Mass = moles × molar mass

Mass = 0.0743 mol × 65.38 g/mol
Mass = 4.854 g

Therefore, approximately 4.854 grams of Zn have been consumed.