# what volume of hydrogen will be produced if 100cm3 of ammonia is completely decomposed at constant temperature and pressure.

## p V = n R T

p/RT = n/V = constant here

n of H2/V of H2 = n of NH3/V of NH3

V of H2 = (n of H2/ n of NH3)100 cm^3

for every 2 mols of NH3 you get 3 mols of H2
so
n of H2/n of NH3 = 1.5
so

V = 1.5 * 100 = 150 cm^3

## 2NH3 ==> N2 + 3H2

When working with gases one can use volume directly as mols and not go through the conversion step of mols = L/22.4.

100 cc NH3 x (3 mols H2/2 mols NH3) = 100 x 3/2 = ? cc H2

## To determine the volume of hydrogen produced when ammonia is completely decomposed, we first need to balance the equation for the decomposition reaction of ammonia:

2NH₃ → 3H₂

The balanced equation shows that 2 moles of ammonia (NH₃) decompose to produce 3 moles of hydrogen gas (H₂).

To find the volume of hydrogen gas produced, we need to know the number of moles of ammonia. Since we are given the volume (100 cm³) of ammonia, we'll use the ideal gas law to convert it to moles. The ideal gas law equation is:

PV = nRT

Where:
P is the pressure of the gas
V is the volume of the gas
n is the number of moles of the gas
R is the ideal gas constant
T is the temperature of the gas

In this case, we have the volume (V) of ammonia and need to find the number of moles (n) of ammonia. Given that the temperature and pressure are constant, we can rearrange the ideal gas law equation to solve for n:

n = PV / RT

Now, substitute the given values into the equation:

P = constant pressure (we'll assume 1 atm)
V = 100 cm³ (convert to liters by dividing by 1000: V = 0.1 L)
R = ideal gas constant (0.0821 L·atm/(K·mol))
T = constant temperature (in Kelvin)

After substituting all the values, you'll have the number of moles (n) of ammonia.

Next, since the balanced equation tells us that 2 moles of ammonia decompose to produce 3 moles of hydrogen gas, we can use the mole ratio to calculate the number of moles of hydrogen gas.

Finally, to find the volume of hydrogen gas produced, you can use the ideal gas law again, this time with the known number of moles of hydrogen gas. Assume the same pressure and temperature for the reaction, and rearrange the ideal gas law equation to solve for volume (V):

V = nRT / P

Substitute the calculated number of moles of hydrogen gas (from the mole ratio) and the given values of P and T into the equation to find the volume of hydrogen gas produced.