4
N
a
+
O
2
→
2
N
a
2
O
.
By the stoichiometry of this reaction if 5 mol natrium react, then 2.5 mol
N
a
2
O
should result.
Explanation:
The molecular mass of natrium oxide is
61.98
g
⋅
m
o
l
−
1
. If
5
m
o
l
natrium react, then
5
2
m
o
l
×
61.98
g
⋅
m
o
l
−
1
=
154.95
g
natrium oxide should result.
So what have I done here? First, I had a balanced chemical equation (this is the important step; is it balanced?). Then I used the stoichiometry to get the molar quantity of product, and converted this molar quantity to mass. If this is not clear, I am willing to have another go
Answer:

Explanation:
In a single-displacement reaction, one element exchanges partners with another element in a compound.

This is a single-displacement reaction, because the element Fe exchanges partners with H in HCl.

This is not a single-displacement reaction, because it is a reaction between two compounds.
This is a double displacement reaction in which the K⁺ and H⁺ cations change partners with the anions.

This is not a single-displacement reaction. It is another double displacement reaction, in which the Na⁺ and H⁺ cations change partners with the anions.

This is a single-displacement reaction, because the element Ca exchanges partners with H in H₂O.
are not single-displacement reactions.
Answer:
In these lessons, students become familiar with the four key periods of growth and human development: infancy (birth to 2 years old), early childhood (3 to 8 years old), middle childhood (9 to 11 years old), and adolescence (12 to 18 years old).
Answer:
The reason why Stephanie -who does not consume alcohol but was medicated for coughing- had a high reading when she had her preliminary breath test (PBT) is because the medication contained molecules similar to ethanol (option C).
Explanation:
Breath alcohol content (BAC) is a measure that is performed through the use of special devices, such as the brethalizer, an analyzer for detecting blood alcohol in drivers. Ethanol is a volatile product that, when found in the blood, is partially eliminated by the airways.
<u>The use of certain types of medications may cause a high reading on the breathalyzer because they contain ethanol</u>. This is likely to have happened to Stephanie who was using a cough medicine -which usually has a low ethanol content- and got a positive reading on the breathalyzer.
Answer:
Argument: It is not Safe
Further support to the argument is given below.
Explanation:
Solution:
Argument: It is not Safe
First of all, we all know the ideal gas law:
PV = nRT
And the Boyle's Law states that , if the pressure is increased then, volume will decrease. and if the volume is increased then pressure will decrease.
V is inversely proportional to Pressure of the gas.
So, in this case, Let's suppose we have toxic solution of methyl alcohol in the bottle which is tightly closed. It means pressure in the bottle is high, hence the volume is less.
If in this scenario someone, leave the bottle open in the laboratory and as it is given that the level of solution will drastically decrease. It means it is volatile in nature and is converted into gaseous form and we know now that the open bottle has now less pressure. Hence the volume of the gas will be higher and now it can spread to every corner of the laboratory. And it is very dangerous.