Answer:
107g
Explanation:
Magnesium fluoride (MgF₂) has a molecular mass of:
Mg: 24,305 g/mol × 1 = 24,305 g/mol
F: 18,998 g/mol × 2 = 37,996 g/mol
MgF₂ = 24,305g/mol + 37,996g/mol = 62,301g/mol. That means the mass of 1,72 mol of MgF₂ is:
1,72 mol F₂ × (62,301g / 1mol) = <em>107g</em>
<em />
I hope it helps!
Answer:
665 kJ
Explanation:
We assume that carbohydrates and protein each have 4 kilocalories per gram, and that fat has 9 kilocalories per gram. Then the number of kilocalories in the peanut butter is ...
4(6 +9) +9(11) = 159 . . . . kilocalories
Each kilocalorie translates to 4.184 kilojoules, so the total is ...
(159 kCal)(4.184 kJ/kCal) = 665.256 kJ
2 Tbsp of crunchy peanut butter contains about 665 kJ of energy.
