Question

A flask contains 6g hydrogen gas and 64 g oxygen at rtp the partial pressure of hydrogen gas in the flask of the total pressure (p)will be

A.2/3p
B.3/5p
C.2/5p
D.1/3p
Answer this with reason

Answer 1

B.3/5p

Step-by-step explanation:

For this question, we have to remember "Dalton's Law of Partial Pressures". This law says that the pressure of the mixture would be equal to the sum of the partial pressure of each gas.

Additionally, we have a proportional relationship between moles and pressure. In other words, more moles indicate more pressure and vice-versa.

`P_i=P_t_o_t_a_l*X_i`

Where:

`P_i`=Partial pressure

`P_t_o_t_a_l`=Total pressure

`X_i`=mole fraction

With this in mind, we can work with the moles of each compound if we want to analyze the pressure. With the molar mass of each compound we can calculate the moles:

moles of hydrogen gas

The molar mass of hydrogen gas (
`H_2`) is 2 g/mol, so:

`6g~H_2(1~mol~H_2)/(2~g~H_2)=~3~mol~H_2`

moles of oxygen gas

The molar mass of oxygen gas (
`O_2`) is 32 g/mol, so:

`64g~H_2(1~mol~H_2)/(32~g~H_2)=~2~mol~O_2`

Now, total moles are:

Total moles = 2 + 3 = 5

With this value, we can write the partial pressure expression for each gas:

`P_H_2=(3)/(5)*P_t_o_t_a_l`

`P_O_2=(2)/(5)*P_t_o_t_a_l`

So, the answer would be 3/5P.

I hope it helps!