Answer:
Mass of iron oxide: 79.85 g
Explanation:
Given data:
Mass of iron = 112 g
Mass of O₂ = 24 g
Mass of iron oxide formed = ?
Solution:
4Fe + 3O₂ → 2Fe₂O₃
Number of moles of Fe:
Number of moles = mass/ molar mass
Number of moles = 112 g/ 55.85 g/mol
Number of moles = 2 mol
Number of moles of O₂:
Number of moles = mass/ molar mass
Number of moles = 24 g/ 32 g/mol
Number of moles = 0.75 mol
Now we will compare the moles of oxygen and iron with iron oxide.
Fe : Fe₂O₃
4 : 2
2 : 2/4×2 = 1
O₂ : Fe₂O₃
3 : 2
0.75 : 2/3×0.75 = 0.5
The number of moles of iron oxide formed by oxygen are less thus it will be limiting reactant.
Mass of iron oxide:
Mass = number of moles × molar mass
Mass = 0.5 mol × 159.69 g/mol
Mass = 79.85 g
6.5-7.5 i believe was right
<u>The S.I unit for the given term:</u>
Mass is expressed in kilogram (kg)
temperature is expressed in kelvin (K)
Time is expressed in seconds (s)
Current is expressed in ampere (A)
<u>Explanation:</u>
<u>Current:
</u>
The current can be defined as the electric charge flow in the surface (means ratio of charge per unit time). It is measured in ampere (A)

<u>Temperature:
</u>
Kelvin (K), the general temperature unit in the international standard units system. The Kelvin scale is an absolute thermodynamic temperature scale that uses absolute zero, a temperature at which all thermal movements end with a classic description of thermodynamics.
<u>Mass:
</u>
Mass is both a feature of the objects weight and its resistance measurement to accelerate under the influence of pure force. The mass of the object also determines the gravitational force. The basic unit of mass is kilogram (kg)
<u>Time:
</u>
Time is the measurement of how much distance the objects takes to travel from one to another (speed). It is expressed in seconds (s).
Answer:
C₂H₄O₂
Explanation:
Step 1: Divide each percentage by the atomic mass of the element
C: 40.00/12.01 = 3.331
H: 6.67/1.01 = 6.60
O: 53.33/16.00 = 3.333
Step 2: Divide all the numbers by the smallest one
C: 3.331/3.331 = 1
H: 6.60/3.331 ≈ 2
O: 3.333/3.331 ≈ 1
The empirical formula is CH₂O, with a molecular weight of 12 g/mol + 2 × 1 g/mol + 16 g/mol = 30 g/mol. The molecular weight of the compound must be a product of 30, such as 60 (between 55 and 62 g/mol). Since we have to multiply by 2 (30 to 60) to get to the molecular weight of the compound, we also have to multiply the empirical formula by 2 to get the chemical formula of the compound.
CH₂O × 2 = C₂H₄O₂