Most of a society's funding will come from their Membership Fees. The fees can either be charged annually or they can be a one off payment to cover the duration of the course; for example, a life membership of £10. Life membership has the advantage that it works out cheaper for the students and it also saves you having to collect membership fees every year. However, do remember that this fee covers the 3 - 4 year period, so you will need to reflect this in the annual budget to ensure that you do not get a deficit over the later years of membership.
You may be able to get funding from the Students' Union but do be aware that different SUs have different rules. Generally, if your society is affiliated to the SU they will allocate you a budget and this may vary each year. They will hold the account and only certain committee members, usually the treasurer and the president, will have access to it. The signatures of both these officials will be required to make a claim and never assume that the SU will reimburse you for any expenditure.
Departments and External Sponsorship
Other sources of funding include your chemistry department, which may be willing to contribute to the funding of the society. You could also try to get external sponsorship from companies that have research contacts in your department as well as any other local companies or national companies.
You can try approaching these companies, asking them whether they would like to provide any funding or assistance to your society. If so, you can promote their company at your events. Do be aware that some companies, particularly the larger ones, may get a lot of requests so don't be disheartened by initial rejection. They may keep your letter on file, so a polite reply thanking them for their attention may work wonders in the future. Remember to aim high - you may be surprised!
As was previously explained, the RSC can provide some funding. There is a lecture/event grant of up to £100 available for your society each year. There is an extra grant that you can bid for of up to £500. There are also other departments in the RSC who may be able to provide additional funding.
Going It Alone
Some Student Unions may wipe your account slate clean during the summer, which means that if you have any funds left over you may lose them. Therefore, it is worth knowing that you are entitled to hold your account at a high street bank. However, a word of caution, some SUs may not approve and may well close your account at the Union. There are certain advantages to having a separate account; for a start, you can keep funds that you have made over the year and banks may be prepared to discuss overdraft terms with you. You will need to do some research about which bank has the best deal and there is no guarantee that the bank will give you an account. Most importantly, if you do get into financial difficulties, then you are the one that has to sort it out.
This option is for advanced societies and the RSC can accept no responsibility for any consequences to the society incurred from this advice.