Question

atomic weight of element is 27. valency of the element is 3. vapour density of its volatile chloride will be

Answer 1

In order to find the vapor density of aluminium chloride, you must first calculate its molar mass. Another look in the periodic table will show that chlorine has a molar mass of approximately

35.45 g mol−1

.

The molar mass of the compound will be

1×27 g mol−1+3×35.45 g mol−1=133.35 g mol−1

You can take the molar mass of hydrogen gas to be approximately

2gmol−1

, which means that the vapor density of the aluminium chloride will be

vapor density=133.35g mol−12g mol−1=∣∣ ∣∣¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯¯aa66.675aa∣∣−−−−−−−−−−

SIDE NOTE The actual answer will probably vary a bit depending on the value you pick for the molar mass of chlorine. For example, if you take

35.5 g mol−1

Answer 2

I hope you understand

.