wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

Solutions of alkali metals in liquid ammonia at 33oC conduct electricity without chemical reaction at the electrodes. Hence, conductivity should :

A
increase as temperature is lowered
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
B
decrease as temperature is lowered
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
remain constant on changing the temperature
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
there is always interaction of alkali metal with liquid ammonia
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is A increase as temperature is lowered
Conductivity should increase as the temperature is lowered because the bandgap in the metal is small and thus the electrons can easily take a leap to the conduction band and conduct electricity but with an increase in temperature, the thermal motion makes the electrons to collide and disturb the free flow.

Thus, conductivity is decreased. However, with a decrease in temperature, the thermal effect is nullified and the electrons can flow smoothly without hindrance and thus conductivity increases.

In semiconductors, the bandgap is big but small enough for few electrons to take a leap to the conduction band and conduct electricity to some extent.

However, with an increase in temperature, they get charged with thermal energy which is sufficient to overcome the energy barrier and leap to the conduction band and thus, their conductivity increases.

Hence, the correct option is A

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Group 1 - Chemical Properties
CHEMISTRY
Watch in App
Join BYJU'S Learning Program
CrossIcon