Inheritance tax allowances

Good afternoon. I have two questions. 1) My father died in 1987, leaving all his property including their house to my mother. When my mother dies, is any of his inheritance tax nil-rate or property rate applicable to my mother's estate? 2) My mother owns her house but has moved to a care home and the house will have to be sold to pay the fees. Does this mean that her £175,000 property allowance is lost, or can it be allowed against her estate? Any help gratefully received! A

​​​​​​Hi,
Please contact the Inheritance Tax team for advice.
Inheritance Tax: general enquiries
Thank you.