A student measures out 100 grams of potassium bromide (KBr). How many moles would this be?
A. 100 g /119 g/mol = 0.84 moles
B. 100 g x 119 g/mol = 11, 900 moles
C. 100 g /54 g/mol = 1.85 moles
D. 100 g x 54 g/mol = 5400 moles
A. 100 g /119 g/mol = 0.84 moles
To calculate the number of moles, we need to use the molar mass of potassium bromide (KBr), which is 119 g/mol.
Dividing the given mass of 100 grams by the molar mass of KBr, we get:
100 g / 119 g/mol = 0.84 moles
Therefore, the correct answer is A. 100 g / 119 g/mol = 0.84 moles.