Answer:
F2 is the limiting reactant
27.6 grams of NaF is produced.
Explanation:
Balance the equation first.
2Na+ F2 ---> 2NaF
To find the limiting reactant, solve for how much NaF can be produced with Na and F2
12.5g F2 x (1 mole F2/ 38.00 grams F2)x (2 mole NaF/ 1 mole F2)
=0.658 moles NaF
16.2g Na x (1 mole Na/ 22.99 grams Na)x (2 mole NaF/ 2 mole Na)
=0.705 moles NaF
Since F2 produced the least NaF, F2 is the limiting reactant.
Now, to find how much NaF there is, use the moles solved above with F2 as the limiting reactant.
0.658 moles NaF x (41.99 grams NaF/ 1 mole NaF)= 27.6 moles NaF
27.6 moles of NaF would be theoretically produced.
Boiling point of a compound is determined by the strength of intermolecular forces of attraction between the molecules present in it. Stronger the intermolecular forces of attraction, higher will be the boiling point.
Ionic compounds show ion-ion interactions which are the strongest among all. Ion-dipole interactions are shown when ionic solutes are dissolved in polar solvents. Hydrogen bonding is also a relatively stronger force that is present between H atom and an electronegative atom like F, O and N(
) . All polar molecules show dipole-dipole interaction (
and 
). Dispersion forces are the weakest intermolecular forces due to momentary dipoles between electron clouds and nucleus.
Among the given compounds, 
has dispersion forces as the major intermolecular forces of attraction. So they they exhibit the weakest IMF, hence have the lowest boiling point.
Answer:
0.0250 g.
Explanation:
∵ no. of moles (n) = mass / molar mass.
<em>∴ mass of Vitamine C = (n)(molar mass)</em> = (0.000142 mol)(176.12 g/mol) = 0.02501 g = <em>0.0250 g. "three significant figures"</em>
In one mole of C7H18 there are 18 moles of H (the number folowing the H)*
>> the ratio is 1:18
In 5.2 moles of C7H18 there are x moles of H
>> the ratio is 5.2:x
Cross multiply the two ratios
1x = 18×5.2
x = 93.6 moles of H
>> In 5.2 moles of C7H18 there are 93.6 moles of H
* This isnt a rule that you can always use.
However to find the mole of a certain element in a certain molucle all you have to do is count how many moles of the element are present in the molecule.
>> example1 >> H2O ;
2 H and 1 O
>> example2 >> CH3COOH ; [you add up all the moles of the same element]
(1+1) 2 C , (3+1) 4 H and (1+1) 2 O
>> example3 >> Mg(OH)2 ; [you multiply whetever is in parenthesis by the number after it 2] 1 Mg , (1×2) 2 O and (1×2) 2 H
D. the pressure is not high enough for the electrical current to flow in the right direction and the battery has stalled
