Question

At which temperature nitrogen under $1.00$ atm pressure has the same root mean square speed as that of $CO _{2}$ at STP

• A. $0^{\circ} C$
• B. $27^{\circ} C$
• C. $-99^{\circ} C$
• D. $-200^{\circ} C$

Answer 1

Answer: (C)

Let RMS speed of nitrogen at $T K$ be $u$ and is equal to that of $CO _{2}$ at STP
$u=\sqrt{\frac{3 R T}{28}}=\sqrt{\frac{3 R \times 273}{44}}$
$T=\frac{273 \times 28}{44}$
$=173.73\, K =-99.27^{\circ} C$