# How do you dispose of K2SO4 and MnSO4? [closed]

I want to do an experiment by showing how generated oxygen can affect an ember.

I saw on the video that adding peroxide and potassium permanganate will do this.

$$\ce{2 KMnO4 + 3 H2SO4 + 5H2O2 = 2 MnSO4 + K2SO4 + 5O2 + 8H2O}$$

If I were to do this at home, how should I dispose of the solution afterwards?

Can I put it down the sink or is it considered a hazardous material and appropriate disposal measures need to be taken?

• Not particularly hazardous. – Mithoron Jul 10 '20 at 15:51
• Using H2O2 and a catalyst (e.g. potato) instead would avoid most of the reactants, which are hazardous if sufficiently concentrated. We can't answer questions about personal safety on this site. – Karsten Theis Jul 10 '20 at 16:17
• Thank you for your comment. Are you suggesting that I could get a similar reaction (lots of generated oxygen) using a pulverized potato instead of the potassium permanganate? What would be the reaction formula? – Tolure Jul 10 '20 at 16:23
• Check out MSDS of potassium sulfate and manganese sulfate – Nilay Ghosh Jul 10 '20 at 16:53
• @Tolure, Potato (or horseradish) are catalysts, not the source of oxygen. – DrMoishe Pippik Jul 10 '20 at 19:36

The problem is the Manganese ion presence (see, for example, this article) as Manganese sulfate is fairly soluble.

Suggested remedy: Add inexpensive Washing Soda (Na2CO3) to the solution as:

$$\ce{MnSO4 (aq) + Na2CO3 (aq) -> Na2SO4 (aq) + MnCO3 (s)}$$

where the created Manganese carbonate is, according to Wikipedia, to quote:

It is a pale pink, water-insoluble solid.

As discussed in the comments, always check the Material Safety Data Sheet (MSDS) for any compound if you are unsure of proper handling or disposal methods.

Whether or not something may be poured down the drain is a function of local municipal by-laws rather than actual toxicity or any other dangers, however, so check the municipals bylaws for your area.

That said, the products of the reaction are quite soluble in water and are used both in fertilizers and in food suppliments for both humans and livestock and are not prone to causing corrosion problems with most materials of construction used in sewage systems. So you are unlikely to blow up or clog your drains by flushing it down the sink.

• (+1) Clear, concise and correct! – Ed V Jul 12 '20 at 1:46