Answer: a biome is defined by its biogeography, temperature, and precipitation
Explanation:
Wish I can help, but I don't take chemistry. :(
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Answer:
26.95 %
Explanation:
Air contains the highest percentage of oxygen and nitrogen gases. Magnesium then combines with both of the gases:


Firstly, find the total number of moles of magnesium metal:

Let's say that x mol react in the first reaction and y mol react in the second reaction. This means:

According to stoichiometry, we form:

Multiplying moles by the molar mass of each substance will yield mass. This means we form a total of:

The total mass is given, so we have our second equation to solve:

We have two unknowns and two equations, we may then solve:


Express y from the first equation:

Substitute into the second equation:





Moles of nitride formed:

Convert this to mass:

Find the percentage:

Number of moles of sodium reacted is 2 moles. 0.04598 Kg is the mass of sodium that reacted.
Mole fraction is 1 mole ratio is 1:1
Explanation:
Balanced chemical reaction:
2 Na + 2H20 ⇒ 2NaOH + H2 (gas)
atomic mass of sodium = 22.99 g/mol
from the reaction it can be seen that 2 moles of sodium reacted to form 2 moles of sodium hydroxide soluition.
The mass of sodium reacted can be calculated from the formula:
mass = atomic mass of one mole x number of moles
mass = 22.99 x 2
= 45.98 grams is the mass of sodium, to convert it into kilograms it is divided by 1000
= 0.04598 Kg is the mass of sodium that reacted.
Mole fraction formula is:
= mole fraction ( solute Na = 2 moles, solution is NaOH =2 moles)
putting the values:
= 1 mole ratio is 1:1