I am connecting a 74ls151 to rpi 3 and what to use it as a demultiplexer for switching mpu6050 on/off. Can the 74ls151 be used as demultiplexer?
No it cannot be used as it does not have a bi-directional mechanism. It can be used to multiple between devices that send data to the raspberry pi or arduino, but it cannot receive any data or voltage from the raspberry pi or arduino. So, it is uni-directional.