To add to Captain Amazing’s response, it is generally true that any money you pay to a government entity goes into its general fund. Sometimes this is hidden in order to make a new tax more palatable: “All taxes on the internet will be used to provide computer access to the underpriveleged.” But it all goes into one pot and is disbursed according to the budget that the legislature determines.
The applicable adjective here is that money is “fungible: of such a nature that one part may be used in place of another part in the satisfaction of an obligation”.
Here in Washington state, for example, the proceeds from the state lottery are supposed to be used for education. But there’s no law that says the legislature can’t then reduce the education budget from other sources by exactly that amount. The net result is that the lottery money can be used for whatever they want.
The classic example is the Social Security fund. There is no such thing. Social Security revenues, just like any other taxes, are collected and banked by the government. Social Security payments are paid out by the government. But there’s not a special place where the Social Security money sits, waiting to be disbursed. It’s all one pile of money, intermixed with your income and other taxes. The only place the Social Security fund exists is on paper. The money itself is already spent. The big breakthrough in balancing the budget was that it was balanced even if you took the Social Security surplus into account.
Social Security was (and is) sold to the American public as some sort of escrow account where your contributions are put in a safe place for future use. That’s a comforting fiction, if you like, but the safe place they put them is in the hands of your legislators, not always noted for putting your interests ahead of all other considerations.