Answer: 52.8 g of 
Explanation:
To calculate the moles, we use the equation:
a) moles of octane
b) moles of oxygen
According to stoichiometry :
2 moles of 
require 25 moles of 
Thus 0.150 moles of require=
of
Thus is the limiting reagent as it limits the formation of product and is the excess reagent.
As 2 moles of give = 16 moles of
Thus 0.150 moles of give =
of
Mass of 
Thus 52.8 g of will be produced from the given masses of both reactants.
What's the problem ? Hardness is not the definition of a metal.
You need to expand your thinking. EVERY element is solid, liquid, and gas, over different ranges of temperature ... including all of the metals. There are only TWO elements that are liquid AT ROOM TEMPERATURE, and mercury is one of them. But on a mild day at the south pole, mercury is solid too.
Answer:
0.164541341 g H2
Explanation:
1) Convert grams to moles by dividing by RMM of Magnesium (24.31g).
2g Mg * (1 mol Mg / 24.31 g Mg) = 0.082270671 mol of Mg
2) Use the balanced equation's ratio of 1 mol Mg: 1 mol H2.
0.082270671 mol of Mg = 0.082270671 mol of H2
3) Convert the mol of H2 back into grams by multiplying by H2's RMM (2 g).
0.082270671 mol of H2 * 2 g H2 = 0.164541341 g H2
* Answer can be rounded to your liking *
initial condition : Vi = 4.700 L , Ti = 71.0ºC +273 => 344 K
final condition : Vf = 3.300 L , Tf = ?
Pressure is constant:
According to charle's law , volume is directly proportional to temperature at constant pressure !
Hence Vi / Ti = Vf / Tf
4.700 L / 344 K = 3.300 L / Tf
Tf = 3.300 L * 344 K / 4.700 L
Tf = 1135200 / 4.700
Tf = 241.53 K
Tf = 241.53 - 273
Tf = -31.47ºC
Answer is: c. 1.204 × 10²⁴ atoms
of carbon.
n(C) = 2 mol; amount of substance of carbon.
Na = 6.02·10²³ 1/mol; Avogadro constant (the number of constituent particles, in this example atoms, that are contained in the amount of substance given by one mole).
N(C) = n(C) · Na.
N(C) = 2 mol · 6.02·10²³ 1/mol.
N(C) = 12.04·10²³ = 1.204·10²⁴; number of carbon atoms in a sample.
