Hello!
To find the mass of helium, we need to multiply the total moles by the mass of helium. We are given 2.714 moles of helium, and the mass of helium is about 4.00 grams. Now, we multiply the two values together to get the grams.
2.714 moles x 4.00 grams = 10.856 grams
According to the number of significant figures, 2.714 moles of helium has a mass of 10.9 grams (exact value: 10.856 grams).
To count the number of valence electrons we look at the electronic configuration and add the electrons form the electronic shell with the highest principal quantum number.
Rb: [Kr] 5s¹ - 1 valence electron
Xe: [Kr] 5s² 4d¹⁰ 5p⁶ - 8 valence electrons
Sb: [Kr] 5s² 4d¹⁰ 5p³ - 5 valence electrons
I: [Kr] 5s² 4d¹⁰ 5p⁵ - 7 valence electrons
In: [Kr] 5s² 4d¹⁰ 5p¹ - 3 valence electrons
Rank from most to fewest valence electrons:
Xe > I > Sb > In > Rb
Answer:
A) 0.95 mol
Explanation:
We will assume the gas given off in the fermentation is an ideal gas because that allows us to use the ideal gas equation.
PV = nRT
First let's convert all measurements to units that we can use
P = 702 mmHg * 1 atm/760 mmHg = 0.92368 atm
V = 25.0 L
R = 0.08206 L-atm/mol-K
T = 22.5 °C +273.15 = 295.65 K
PV = nRT
0.92368 atm * 25.0 L = n * 0.08206 L-atm/mol-K * 295.65 K
n = 0.9518 mol
Answer: The force on the firefly
The unfortunate firefly hitting the bus does not change the velocity of the bus very much. Technically there is a change, but it's so very small and miniscule that it barely registers. To any casual observer not paying very close attention, they don't notice anything at all. So effectively the force on the firefly is a lot greater since the firefly got the worst end of the deal.
So in short, we look at the velocity of each object and see which velocity changed the most. In this case, the firefly's velocity changed from whatever speed it was flying to 0 when it stops flying all together. That's why the force is greater on the bug.
Answer:
Explanation:
Hello,
In this case, since the reaction between potassium hydroxide and nitric acid is:
We can see a 1:1 mole ratio between the acid and base, therefore, for the titration analysis, we find the following equality at the equivalence point:
That in terms of molarities and volumes is:
Thus, solving the molarity of the base (KOH), we obtain:
Regards.
