No. The voltage is different. Even with something like a phone you will need a special plug to use.
Yes
If you buy an adapter
Hong Kong uses the same electrical output/sockets as the UK so US appliances will need an adaptor.
Yes, they will work anywhere.
Not without an adapter.
Yes, but you will need an adapter to plug it in as the electrical system is different in Ireland.
Yes.
Unlikely- European countries run on 240 volts which is about double the US standard.
Ireland uses Type G electrical outlets for its appliances and devices. These outlets have three rectangular prongs and are compatible with plugs that have three rectangular prongs as well.
yes they do! :) Europe uses a different voltage than the US and also has different shaped electrical plugs, so you can't just plug a European appliance into an American electrical outlet. If you can get the right kind of current, then the appliances will still work.
In general, no, European appliances will not work in the US. Small appliances will have a Eurocord plug, which expects 230 volts and 50 Hz. With a transformer, you can convert a US outlet to a Euro outlet, but for many appliances the difference between 50 Hz and 60 Hz will prevent them working in the US.
No, not without a converter. Australia's current is 240 volts at 50 hertz.