Calculate the molarity and molality of 49.0 wt% hf, assuming a density of 1.16 g/ml.

Molarity 28.42
Molality = 24.5 

To answer this question, it would be easier if you assume that the liquid volume is 1L. You also need to know that HF weight is 20 (fluor=19, helium=1). Then you need to calculate how many moles of HF inside the solution. The calculation would be:

1L x (1000ml/L) x 1.16g/ml x (49g/100g) / (20g/mole)= 28.42 mole

Then the solution molarity: 28.42mole / 1L= 28.42
Then the solution molality: 28.42mole / (1L x 1000ml/L x 1.16g/ml) = 24.5