Answer: Molarity of
anions in the chemist's solution is 0.0104 M
Explanation:
Molarity : It is defined as the number of moles of solute present per liter of the solution.
Formula used :

where,
n= moles of solute
= volume of solution in ml = 100 ml
Now put all the given values in the formula of molarity, we get

Therefore, the molarity of solution will be 

As 1 mole of
gives 2 moles of 
Thus
moles of
gives =
Thus the molarity of
anions in the chemist's solution is 0.0104 M
The purpose of a chemical equation is to relate the amounts of reactants to the amounts of products based on the rate each is consumed. In this problem, one mole of sulfuric acid is consumed along with two moles of sodium cyanide to produce two moles of hydrocyanic acid and one mole of sodium sulfate. The relationship between sodium cyanide and sodium sulfate is 2:1, meaning that two moles of NaCN is required to produce one mole of sodium sulfate.
To produce 4.2 moles of sodium sulfate, two times this amount of NaCN is required. This means that you would need 8.4 moles of sodium cyanide.
Hope this helps!