# What is the number of moles of KF in a 29-gram sample of the compound?

What is the number of moles of KF in a 29-gram sample of the compound?

(1) 1.0 mol

(2) 2.0 mol

(3) 0.50 mol

(4) 5.0 mol

To find the number of moles, you can look at the reference table Table T and find the formula for moles.

Number of moles = given mass/ gram-formula mass

Therefore let's use first fine the gram formula mass by looking at the periodic table. K has a mass of 39g/mol and F is 18.998 g/mol. Therefore mass of KF = 39+18.998 = 57.998g/mol

this formula : Number of moles = 29g (mass given in the problem) / 57.998 g/mol = 0.5 moles Choice 3 is the correct choice.

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