Question

The number of molecules in 1 cm³ of an ideal gas at 0°C and at a pressure of 10^-5 mm of mercury is ______.

पर्याय

• 2.7 × 10¹¹

• 3.5 × 10¹¹

• 6.0 × 10²³

• 6 × 10¹²

Answer 1

The number of molecules in 1 cm³ of an ideal gas at 0°C and at a pressure of 10^-5 mm of mercury is 3.5 × 10¹¹.

Explanation:

PV = nRT

⇒ PV = `"N"/"N"_"A"`RT

Avogadro's number = 6.0 × 10²³ particles per mole

760 mm mercury pressure = 10⁵ atm

So, 10^–5 mm pressure = `(10^-5xx10^5)/760` atm

⇒ N = `("PVN"_"A")/"RT"`

= `([10^-5/760xx10^5]xx[1xx10^-6]xx6xx10^23)/(8.3xx237)`

N = `1/283556xx10^17`

= 3.5 × 10¹¹