1) Reaction: 3Mg + N₂ → Mg₃N₂.
m(Mg) = 0,225 g
n(Mg) = 0,225 g ÷ 24,3 g/mol = 0,009 mol.
n(Mg) : n(N₂) = 3 : 1
n₁(N₂) = 0,003 mol.
n₂(N₂) = 0,5331 ÷ 28 = 0,019 mol.
n₃(N₂) = 0,019 mol - 0,003 mol = 0,016, m(N₂) = 0,016mol·28g/mol=0,4467g.
or simpler: m(N₂) = 0,225 g + 0,5331 - 0,3114 g = 0,4467 g.
2) Answer is: 6 <span>of fluorine atoms are combined with one uranium atom.
</span>m(U) = 209 g.
m(F) = 100 g.
n(U) = m(U) ÷ M(U)
n(U) = 209 g ÷ 238 g/mol.
n(U) = 0,878 mol.
n(F) = m(F) ÷ M(F)
n(F) = 5,263 mol
n(U) : n(F) = 0,878 mol : 5,263 mol /:0,878.
n(U) : n(F) = 1 : 6.
n - amount of substance
Pushing down on the piston
causes an increase in pressure and a decrease in the volume of the gas in the
cylinder. This is BEST explained by the fact that the pressure is always
inversely proportional with volume at constant temperature and number of moles
of substance.
You should know that 1 mole has 6.02 x 10*23 atoms (Avogadro)...so if you have one atom with 4.48 *10-23 g...then 6.02 *10*23 how many??.. try the rule of 3...answer A is 26,9696 g. For answer b, first of all covert the 5000 kg to 5000000 g (you can write 5 x 10*6)..afterwards make the rule of 3.. if 26,9696 g they are in 1 mole, the mass of the plane 5 x 10*6 g... how many moles?.. be careful with g and the kg.!!.. Answer B should be 185393, 92 moles.
You can separate out the canola oil easily, because it has cooled down enough to turn back into a solid.
Answer:
Classifying stars according to their spectrum is a very powerful way to begin to understand how they work. As we said last time, the spectral sequence O, B, A, F, G, K, M is a temperature sequence, with the hottest stars being of type O (surface temperatures 30,000-40,000 K), and the coolest stars being of type M (surface temperatures around 3,000 K). Because hot stars are blue, and cool stars are red, the temperature sequence is also a color sequence. It is sometimes helpful, though, to classify objects according to two different properties. Let's say we try to classify stars according to their apparent brightness, also. We could make a plot with color on one axis, and apparent brightness on the other axis, like this:
Explanation:
