Question

$N _ { 2 }$ is found in a litre flask under pressure and is found in another 3 litre flask under pressure. If the two flasks are connected, the resultant pressures is.

• A. 310 kPa
• B. 210 kPa
• C. 420 kPa
• D. 365 kPa (e) 265 kPa

Answer 1

(e)

Sol. Total volume of two flasks = 1+ 3 = 4

If $P _ { 1 }$ the pressure of gas $N _ { 2 }$in the mixture of $N _ { 2 }$and then

P = 100 kPa , $P _ { 1 } = ?$ , V = 1 litre , $V _ { 1 } = 4$ litre

applying Boyle's law $P V = P _ { 1 } V _ { 1 }$

100 × 1 = $P _ { 1 } \times 4$; $P _ { 1 } = 25$

If $P _ { 2 }$ is the pressure of $P _ { 2 } \times 4$; $P _ { 2 } = 240$

Hence, Total pressure $P = P _ { 1 } + P _ { 2 } = 25 + 240$

$= 265 \mathrm { kPa }$