Zinc metal reacts with HCL similarly to magnesium: Zn(s) + 2HCL(aq) = ZnCl2(aq) + H2(g). the H2 gas produced was collected over water at 25 degrees Celsius and had a volume of 7.80L at 0.980 atm. How many grams of Zn were consumed in the reaction? (Vapor pressure of water at 25C = 23.8mmHg)

please show me how to get the answer

Zn+ 2HCl ==> H2 + ZnCl2

Use PV = nRT and solve for n = number of mols H2.
Substitute [0.980 atm - (23.8/760)] for P.
Don't forget T must be in kelvin.

After you have obtained n, convert from mols H2 to mols Zn using the coefficients in the balanced equation. The g Zn = mols Zn x molar mass Zn.

To find the number of grams of Zn consumed in the reaction, we will use the ideal gas law equation: PV = nRT. Here's how you can solve the problem step-by-step:

Step 1: Convert the temperature from Celsius to Kelvin.
The given temperature is 25 degrees Celsius. To convert it to Kelvin, add 273 to the Celsius value: 25 + 273 = 298 K.

Step 2: Convert the pressure of H2 gas to atmospheres.
Given pressure = 0.980 atm. No conversion is necessary in this case.

Step 3: Convert the vapor pressure of water from mmHg to atmospheres.
Given vapor pressure = 23.8 mmHg. To convert to atm, divide the value by 760 (since 760 mmHg = 1 atm): 23.8 / 760 = 0.0313 atm.

Step 4: Calculate the pressure of H2 gas over water.
The total pressure of the gas collected is the sum of the atmospheric pressure and the vapor pressure of water:
Total pressure = Given pressure + Vapor pressure = 0.980 + 0.0313 = 1.0113 atm.

Step 5: Rearrange the ideal gas law equation and solve for n (the number of moles of H2 gas).
PV = nRT
n = (PV) / (RT)

Given:
P = 1.0113 atm (total pressure)
V = 7.80 L (volume)
R = 0.0821 L.atm/(mol.K) (gas constant)
T = 298 K (temperature in Kelvin)

Substitute these values into the equation:
n = (1.0113 atm * 7.80 L) / (0.0821 L.atm/(mol.K) * 298 K)

Step 6: Calculate the number of moles of Zn consumed.
According to the balanced equation, the stoichiometry between Zn and H2 is 1:1. This means that the number of moles of Zn consumed is equal to the number of moles of H2 produced.

Step 7: Convert the number of moles of Zn to grams.
To convert moles of Zn to grams, we need to know the molar mass of Zn. The molar mass of Zn is 65.38 g/mol.

Finally, calculate the number of grams of Zn:
Mass (g) = Moles (mol) * Molar mass (g/mol)

Note: You should substitute the value obtained in Step 5 for the number of moles of Zn in this step.

That's it! Just follow these steps, and you'll be able to find the number of grams of Zn consumed in the reaction.