# If 5.6 g of iron powder is completely oxidized to Fe2O3 powder, the mass of oxygen consumed is _____, Its chemical equation is_________

## If 5.6 g of iron powder is completely oxidized to Fe2O3 powder, the mass of oxygen consumed is _____, Its chemical equation is_________

4Fe+3O2====2Fe2O3
The relative atomic mass of iron is 56
The proportion of Fe2O3 is 112 divided by 160, so the mass of Fe2O3 is 8 G
Oxygen mass equals 8 minus 5.6 equals 2.4 grams

### Read the following materials: "the chemical name of quicklime is calcium oxide. ① after mixing quicklime with water, it turns into lime slurry to wipe the walls of the room. ② these lime slurry constantly absorbs carbon dioxide in the air, gradually hardens and turns into calcium carbonate. At the same time, the newly plastered wall slowly becomes wet, as if the lime wall is" sweating " ③ in a room with newly plastered lime walls, a charcoal fire is often burned. Do you want to dry the room? No. It is because there is only 0.03% (volume fraction) of carbon dioxide in the air. Burning a charcoal fire is to increase the content of carbon dioxide in the room and speed up the hardening of lime slurry. "Please according to the relevant information of materials, Combined with the knowledge learned, the three chemical reaction principles in information are expressed by chemical equations ①______； ②______； ③______．

① Quicklime reacts with water to form calcium hydroxide. The chemical equation is Cao + H20 ＾ Ca (OH) 2; ② Carbon dioxide reacts with calcium hydroxide to produce calcium carbonate and water. The chemical equation is: Ca (OH) 2 + CO2 ↓ CaCO3 ↓ + H2O; ③ Carbon reacts with oxygen to form carbon dioxide. The chemical equation is C + O2   Ignite & nbs

### Let the atomic mass of a carbon 12 be x g and the mass of a nitrogen dioxide molecule be a g If the molecular mass of an NO is BG, the relative atomic mass of the oxygen atom (the oxygen atom in No2 molecule and no molecule is the same)

Let the mass of one nitrogen atom be y and the mass of one oxygen atom be Z
Then y + 2Z = a
Y+Z=b
The solution is Z = a-b
The relative atomic mass of the oxygen atom is (a-b) / (1 / 12x) = 12 (a-b) / X
A: the relative atomic mass of the oxygen atom is 12 (a-b) / X

### The ratio of the number of electrons contained in 1.5g NaOH to the number of grams of ammonia is 2 to 1.2. Calculate the number of atoms contained in 5.4ml of water at 4 ℃

1. Solution: the amount of 5g NaOH = 5 / 40 = 0.125mol, the number of electrons contained = 0.125 * (11 + 8 + 1) Na = 2.5na, the ratio of the number of electrons contained in NaOH and ammonia is known to be 2:1, so the number of electrons contained in ammonia = 1.25na, the amount of ammonia = 1.25 / (7 + 1 * 3) =0.125mol, so the mass of ammonia = 0.125 * 17 = 2.125g answer: the ratio of 5g NaOH to the number of electrons contained in 2.125g ammonia is 2:12. Solution: when the density of water is 1g / ml at 4 ℃, the mass of 5.4ml water = 5.4 * 1 = 5.4G, the amount of 5.4ml water = 5.4/18 = 0.3 mol 1mol water (H2O) The number of atoms contained in water = 3Na 0.3mol the number of atoms contained in water = 3Na * 0.3 = 0.9na answer: at 4 ° C, the number of atoms contained in 5.4ml water is 0.9na. Note Na = 6.02 * 10 to the 23rd power

### Find the number of atoms in 18 ml of water at 4 ℃ I want the whole process

At 4 ℃, the density of water is 1g / ml, 18ML water is 18G water
The molar mass of water is 18G / mol, and the amount of substance in 18ML water is 1mol
One water molecule contains three atoms (two hydrogen atoms and one oxygen atom)
Therefore, the number of atoms in 18ML water at 4 ℃ is 3mol, 3Na and 1.806 * 10 ^ 24

### What is the atomic number of 36 ml of water at 4 ° C? How to find it?

At 4 ℃, the water density is 1g / cm3
2mol for 36 ml of water
Atomic number 3Na