Determine the molarity of a solution formed by dissolving 4.00 moles of kbr in enough water to yield 3.00 l of solution.

Molarity (M) is the numer of moles per liter (mol/L)

Both are already given:
mol = 4.00 moles of KBr
L = 3.00 L H2O (water)

Plug them both into the equation:
4.00 mol KBr  = 1.33 M KBr (1.33 because of sig figs)
3.00 L H2O 

30litre of li2o is 1.0002mole approximately 1 mole

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