Answer:
17.76g
Explanation:
We need to write a balanced chemical equation for the reaction:
2Al(OH)3 + 3Ca(NO3)2 ——> 3Ca(OH)2 + 2Al(NO3)3
In the reaction above, it can be seen that 2 moles of aluminum hydroxide yielded 3 moles of calcium hydroxide. This is the theoretical viewpoint.
Now we need to know what actually happened. We need to calculate the actual number of moles of aluminum hydroxide reacted l. We can get this by dividing the mass by the molar mass.
The molar mass of aluminum hydroxide is 27+ 3( 16+1)
= 27 + 51 = 78g/mol
The number of moles is thus: 12.55/78 = 0.16 moles
Now if 2 moles of aluminum hydroxide gave 3 moles of calcium hydroxide, 0.16moles will give : (0.16*3)/2 = 0.24moles
Now we can calculate the mass of calcium hydroxide formed. The mass of calcium hydroxide formed is the number of moles multiplied by the molar mass.
The molar mass of calcium hydroxide is; 40 + 2(17) = 74g/mol
The mass is thus =74 * 0.24 = 17.76g
Answer:
B. How many of each atom are present in the compound
D. the simplified ratio of atoms in relation to each other
Explanation:
In a chemical formula, chemical elements or atoms are represented by a chemical symbol for example Fe for iron and Na for sodium, and the number of each atom is represented by a subscript such as CO2, where 2 is a subscript representing 2 atoms of oxygen.
A subscript represents the number of each atom in the compound and the simplified ratio of atoms in relation to each other. The simplified ratio of atoms in relation to each other means subscript shows the contribution of both the atoms in the compound, for example: N2 + 3H2 => 2NH3, it means the subscript showing the ratio or proportionate of atoms that is 2:2 for both nitrogen and hydrogen.
The subscript is always written below and to the right of the chemical symbol.
Hence, the correct answer is "B. How many of each atom are present in the compound and D. the simplified ratio of atoms in relation to each other"
Human organisms, and animals can also be infected by Ebola
The major carbon sources (reservoirs that release more carbon than absorbed) are: deforestation and fossil fuels
The major carbon sinks (reservoirs that absorb more carbon than released) are:
soil, oceans and plants.
When scientists calculate the amount of carbon dioxide is returned to the atmosphere vs the released the amount of carbon, a large amount is unaccounted for and the total does not add up. This is why scientists believe there is an undiscovered carbon sink somewhere.
Explanation:
first one because absolute dating is a thing for rock layers
