Technically there is only one phase unless you account for a solution where you have a pure liquid with something dissolved in it. Unless you count aqueous as a phase which is just dissolved. Since you are in high school the answer you are looking for is one. <span />
<span> It is important to keep the NaOH solution covered at all time because sodium hydroxide is a very good remover of Carbon dioxide from the air means sodium hydroxide absorbs the carbon dioxide from the air react with that so the concentration of your solution will also change if you uncover the NaOH.
The following reaction occurs when sodium hydroxide reacts with carbon dioxide;
</span><span>2 NaOH(aq) + CO2(g) --> Na3CO3(aq) + H2O(l) </span>
People can reduce their exposure to BPA by washing out plastic cups, buying BPA free plastics. BPA should be kept out because it can cause a chemical interference in the human body
The oceanic crust is about 4 miles thick.