Answer:
5.9 kg
Explanation:
We must work backwards from the second step to work out the mass of oxygen.
1. Second step
Mᵣ: 55.84
Fe₂O₃ + 3CO ⟶ 2Fe + 3CO₂
m/kg: 7.0
(a) Moles of Fe

(b) Moles of CO

However, this is the theoretical yield.
The actual yield is 72. %.
We need more CO and Fe₂O₃ to get the theoretical yield of Fe.
(c) Percent yield

We must use 261 mol of CO to get 7.0 kg of Fe.
2. First step
Mᵣ: 32.00
2C + O₂ ⟶ 2CO
n/mol: 261
(a) Moles of O₂

(b) Mass of O₂

However, this is the theoretical yield.
The actual yield is 71. %.
We need more C and O₂ to get the theoretical yield of CO.
(c) Percent yield

We need 5.9 kg of O₂ to produce 7.0 kg of Fe.
Group 1 contains metals while group 18 contains noble gases.
So group 1 is different from group 18 as they both contains different types of atoms as group 1 contains metals while group 18 contains noble gases.
There is 1 valence shell electron in group 1 , they are highly reactive while valence shell of group 18 is fully filled and they are least reactive .
Answer:
6.6023g
Explanation:
To create a 0.247 M solution required weight of barium hydroxide.
0.247 x 171.346 =42.322g per liter
Therefore required mass for 156g of water = 42.322 x 0.156 = 6.6023g
Answer:
17 protons, 20 neutrons, and 17 electrons.
Explanation:
A periodic table can be defined as the standard arrangement of chemical elements by atomic number, electronic configuration and chemical properties in a tabular form.
Generally, a proper representation of the mass number and atomic number of chemical elements is key and very important in chemistry.
Furthermore, as a rule, it should be noted that the mass number (nucleon number) is always larger than the atomic number(number of proton).
The mass number of this neutral atom of Cl-37 is 37 and we know that the atomic number (number of protons) of chlorine is 17. Also, the atomic number of an element is equal to the number of its electrons.
A neutral atom of Cl-37 has 17 protons, 20 neutrons, and 17 electrons.
Hence, a neutral atom of Cl-37 can be identified based on its number of protons because it represent its atomic number, which is what is used to differentiate an atom of an element from the atom of another chemical element.
In 1871, a Russian Chemist, Dimitri Mendeleev, gave a useful scheme for classification of elements. He presented the first regular periodic table in which elements of similar chemical properties were arranged in eight vertical columns called groups. The horizontal rows of table were called periods. He arranged elements in ascending order of their atomic masses and found that elements having similar chemical properties appeared at regular intervals. This observation was called Periodic Law.