Finding molarity of solution

[Voltman]

Calculate the molarity of the solution below.


2.1 g of NaHCO3 dissolved in 1.00 L of solution.



The answer 0.025 M but I got 0.058 M. Please show complete working out. Thank you!

[Russ]

Molarity is number of moles (n) per litre (L) of solution.
Equation is M = n/L

n(NaHCO3) = 2.1/84

Since there is only 1L of solution, you need to divide by 1 to get the molarity (so the answer is .025)

84 is the formula mass of NaHCO3, derived from the formula;
n = m/M, m = mass and M = Formula Mass