Unless they are specifically rated as 110-240v 50-60Hz on the electrical rating label, they will NOT work without the use of a power converter of some kind. While it's unlikely that they would blow up if you did plug them directly into the mains power supply in Canada, it IS possible.
In all honesty, it's probably best if you gift/sell/junk anything that is rated as only 240Volt 50Hz, such as blenders, vacuum cleaner etc. The rule of thumb tends to be that high power devices will be UK specific, where as low power devices, such as PC, printer, phone chargers etc will be multi standard and may well work in Canada. If you are not sure, ask a qualified electrician.