To find the mass of fluorine in the number of atoms provided, we first divide the number of atoms by Avagadros number (6.02 × 10^23atoms) to get the number of moles in the fluorine atom. That is;

number of moles (n) = number of atoms (nA) ÷ 6.02 × 10^23 atoms

n = 2.542 × 10^26 ÷ 6.02 × 10^23

n = 0.42 × 10^ (26-23)

n = 0.42 × 10^3

n = 4.2 × 10^2moles

Using mole = mass ÷ molar mass

Molar/atomic mass of fluorine (F) = 19g/mol

mass = molar mass × mole

Mass (g) = 19 × 4.2 × 10^2

Mass = 79.8 × 10^2

Mass = 7.98 × 10^3grams.

8 0

2 years ago

8. When a 2.5 mol of sugar (C12H22O11) are added to a certain amount of water the boiling point is raised by 1 Celsius degree. I

Julli [10]

Hey there!:

8) ΔTb = i*Kb*m

m is molality

Since same number of mol is added to same amount of water in both cases

m will be same for both

is 1 for glucose since it is covalent compound

is 4 of Al(NO3)3 as it breaks into 1 Al₃⁺ and 3 NO₃⁻

So, ΔTb will be 4 times in aluminum nitrate case

So, boiling point will change by 4ºC

9) use Q = m* L

L = heat of vaporization so:

T1=T2=100ºC

5.40 * 1000 => 5400 cal/g

Q = 5400 / 540

Q = 10 grams

Hope that thlps!

5 0

2 years ago