The student prepares the NaOH solution of high purity but unknown concentration by taking about 5 mL of the supernatant at the top of the saturated solution adding it to a plastic bottle with about 1 L of freshly distilled or deionized water. The bottom of the solution contains some white solids which are likely to be (select all correct answers

The choices are:

A) water(s)
B) sodium hydrogen sulfate
C) phthalic acid D) CO2 (s)
E) sodium slicate F) sodium hydroxide G) sodium hydrogen carbonate