If 5.61 g of ammonium nitrate (NH4NO3) is dissolved in 155 mL of water to make an instant cold pack, what is the molarity of the resulting solution?

0.452 M

Explanation:

Remember that to get molarity, you have to go thru an equation:

M=mol/V (in liters)

So ...

5.61 g NH4NO3 x 1 mol NH4NO3/80.043 g

=0.0701 mol NH4NO3

Convert mL to L

=155--->0.155 L

Plug in and divide.

0.0701/0.155

=0.452 M