]what is the molarity of a 0.25-liter solution containing 52 grams of hbr?
13 m hbr
2.6 m hbr
0.64 m hbr
0.16 m hbr

There are a number of ways to express concentration of a solution. This includes molarity. Molarity is expressed as the number of moles of solute per volume of the solution. We calculate as follows:

Molarity = 52 g (1 mol / 80.91 g) / 0.25 L = 2.6 mol/L or 2.6 M 

Given:
0.25 liters of solution
52 grams of HBr

Solve for the Molarity.

Molarity is expressed as mol/L. Since the given is in grams, you need to convert it into moles. The formula for finding moles is:

moles=grams/molecular weight

We need to know the molecular weight of HBr. The molecular weight of HBr is 80.91 grams/mole. Next thing that we should do is substitute the values. 

moles=52 grams HBr/(80.91 grams/mol)
         = 0.643mol

So now we have the value of HBr in moles which is 0.643 moles. We can know use the formula in finding molarity and substitute its values (as shown below).

Molarity=0.643mol/0.25L
             =2.6 M HBr

So, the molarity of a 0.25L solution containing 52 grams of HBr is 2.6M.