[awss]

Why do the serum proteins of the milk precipitate when adding calcium carbonate?

There is a video where 1.5 g of calcium carbonate is added to 50 mL of milk, it is gently boiled while the milk is stirred, then it is filtered and the calcium carbonate is left together with the serum proteins on the filter paper. Why is that?

I need to explain that for a school summer project but I have no clue whatsoever. Please help.

[marquis]

Check and see if coagulate isn't a better verb than precipitate.

Many solutions like milk and latex rubber behave this way. Put the solution in a mildly acidic solution and it coagulates.  With latex the solution is usually calcium nitrate, not calcium carbonate.