The chemist the count the number of particles (Atoms, Molecules or Formula Unit) in a given number of moles of a substance by using following relationship.
Moles = # of Particles / 6.022 × 10²³
Or,
# of Particles = Moles × 6.022 × 10²³
So, from above relation it is found that 1 mole of any substance contains exactly 6.022 × 10²³ particles. Greater the number of moles greater will be the number of particles.
10.0gNaCl/2.0Lsolution= 5.0g/L
Answer:

Explanation:
Hello,
In this case, for a first-order reaction, we can firstly compute the rate constant from the given half-life:

In such a way, the integrated first-order law, allows us to compute the final mass of the substance once 10.0 minutes (600 seconds) have passed:

Best regards.