Answer:
Option (2) 2
Explanation:
NO3- + 4H+ + Pb → Pb2+ + NO2 + 2H2O
The equation above can be balance as follow:
There are 3 atoms of the left side and a total of 4 atoms on the right side. It can be balance by putting 2 in front NO3- and 2 in front of NO2 as shown below:
2NO3- + 4H+ + Pb → Pb2+ + 2NO2 + 2H2O
Now the equation is balanced.
The coefficient of NO2 is 2
Na 2Co3
1*23=23. 2*12=24. 6*16=96
23+24+96=143
(23*100)/143. (24*100)/143. (96*100)/143
=16%. =16.7%. =67.1%
Answer:
You may be referring to the gas that makes up 21% of the earth's atmosphere, which is oxygen.
Explanation:
According to NASA, the gases in Earth's atmosphere include:
Nitrogen — 78 percent
Oxygen — 21 percent
Argon — 0.93 percent
Carbon dioxide — 0.04 percent
(Trace amounts of neon, helium, methane, krypton and hydrogen, as well as water vapor)
Answer:
1 gramo de metano aporta 50.125 kilojoules.
1 gramo de metano aporta 48.246 kilojoules.
Explanation:
La cantidad de energía liberada por la combustión de una unidad de masa del hidrocarburo (
), en kilojoules por mol, es igual a la cantidad de energía liberada por mol de compuesto (
), en kilojoules por mol, dividido por su masa molar (
), en gramos por mol:
(1)
A continuación, analizamos cada caso:
Metano
1 gramo de metano aporta 50.125 kilojoules.
Octano
1 gramo de metano aporta 48.246 kilojoules.
<h3>
Answer:</h3>
Balanced equation: 4Fe + 3O₂ → 2Fe₂O₃
Moles of oxygen gas = 9 moles
<h3>
Explanation:</h3>
To answer the question;
- We first write the balanced equation between iron metal and Oxygen
- The balanced equation is given as;
4Fe + 3O₂ → 2Fe₂O₃
- We are given 6 moles of Fe₂O₃
We are required to determine the number of moles of oxygen needed to form 6 moles of Fe₂O₃.
- From the equation, 3 moles of oxygen gas reacts to produce 2 moles of Fe₂O₃
- This means, the mole ratio of O₂ to Fe₂O₃ is 3 : 2
Therefore; Moles of O₂ = Moles of Fe₂O₃ × 3/2
Hence, moles of oxygen = 6 moles × 3/2
= 9 moles
Thus, Moles of Oxygen needed is 9 moles
