Item 21 - A student heated a blue solid which
gave off a gas. When tested, the gas
changed cobalt chloride paper to
pink. Which of the following is a
LIKELY component of the gas?
B.
Carbon dioxide
Hydrogen
Dust particles
Water vapour​

How many moles of magnesium is 3.01 x10^22 atoms of magnesium?

The number to the right of an element's symbol (ex. c-12) identifies the of an isotope.

Achemistry student needs to standardize a fresh solution of sodium hydroxide. he carefully weighs out of oxalic acid , a diprotic acid that can be purchased inexpensively in high purity, and dissolves it in of distilled water. the student then titrates the oxalic acid solution with his sodium hydroxide solution. when the titration reaches the equivalence point, the student finds he has used of sodium hydroxide solution.calculate the molarity of the student's sodium hydroxide solution. be sure your answer has the correct number of significant digits.