Which statement about a partner's loan to the firm is correct?

1. A partner's loan is separate from the partner's capital, and a loan account is maintained for it. 2. Interest on the loan is an expense of the firm, so interest on partner's loan account is debited. 3. The interest is due to the partner and is generally added to the loan amount, so the partner's loan account is credited, not the capital or current account. 4. On closing, the interest is transferred to the profit and loss account, not the appropriation account. 5. Because it is a charge against profit rather than an appropriation, it must be provided whether the firm makes a profit or a loss. 6. That last point is what separates it from interest on capital, salary and commission, all of which require profit. _Source: TN HSC Class 12 Accountancy (Samacheer Kalvi, Govt of Tamil Nadu), Unit 3 "Accounts of Partnership Firms - Fundamentals", §3.9_