Question

A new element $E$ forms a compound with chlorine which contains 1.455 g $Cl$ per $gE$. The specific heat of $E$ was found $0.05cal/g$ . If eq. weight of element is 24, then the value of $x$ in ${ECl}_x$ is:

Answer 1

Atomic mass of $E$ $=\frac{6.4}{\text{specific heat in cal}}=\frac{6.4}{0.05}=128$
1 g of $E$ combines with 1.455 g of chlorine
Equivalent mass of $E$ is the mass of $E$ that combines with 35.5 g of chlorine. The equivalent mass of $E$ will be $\frac{1}{1.455}\times 35.5=24.4$
Valence $=\frac{\text{atomic mass}}{\text{equivalent mass}}=\frac{128}{24.4}=5.2\simeq 5$
Hence, the value of $x$ in $EC{l}_x$ is 5.