Question

use the references to access important values if needed. the percent by mass of chlorine in pncl₂ is %. (enter your answer to four significant figures.) submit answer retry entire group 5 more group attempts remaining

Explanation:

Step1: Find atomic masses

The atomic mass of P (phosphorus) is approximately $30.97\ g/mol$, N (nitrogen) is approximately $14.01\ g/mol$, and Cl (chlorine) is approximately $35.45\ g/mol$.

Step2: Calculate molar mass of $PNCl_2$

$M_{PNCl_2}=30.97 + 14.01+2\times35.45$
$M_{PNCl_2}=30.97 + 14.01 + 70.90=115.88\ g/mol$

Step3: Calculate mass of chlorine in $PNCl_2$

The mass contributed by chlorine is $m_{Cl}=2\times35.45 = 70.90\ g/mol$

Step4: Calculate percent by mass of chlorine

Percent by mass of chlorine $=\frac{m_{Cl}}{M_{PNCl_2}}\times100\%$
$=\frac{70.90}{115.88}\times 100\% \approx 61.18\%$

Answer:

$61.18$