A “super PAC” supporting Hillary Clinton will begin a $10.5 million advertising blitz in Pennsylvania, a crucial battleground state that Donald J. Trump is seeking to win by appealing to white working-class voters.

The wave of spending will begin on July 5 and run through Election Day, in the markets around Philadelphia, Scranton and Pittsburgh. The ad campaign brings the full amount that the PAC, Priorities USA, has reserved on television against Mr. Trump to $117.5 million, according to the group’s spokesman, Justin Barasky.

“This morning Donald Trump cheered a potential economic collapse because it would be good for his bottom line and compared running a country to running a golf course,” Mr. Barasky said, adding that the group was “determined” to keep him from becoming president.

With Pennsylvania added to its list, Priorities will be advertising in nine states. Mr. Trump has yet to air a general election ad, and the super PACs supporting him have not been running spots in battleground states.