Answer:
Na₂CO₃ · 10H₂O
Explanation:
The formula for sodium carbonate hydrate is:
Na₂CO₃ · xH₂O
The unknown "x" is the number of water molecules contained in the hydrate.
To find "x" we have to use the hydrogen percentage in the sample, 7.05 % H.
First we calculate the molecular weight of Na₂CO₃ · xH₂O:
molecular weight of Na₂CO₃ · xH₂O = 23 × 2 + 12 + 16 × 3 + 18x
molecular weight of Na₂CO₃ · xH₂O = 106 + 18x g/mole
Now we devise the fallowing reasoning tanking in account 1 mole of Na₂CO₃ · xH₂O:
if in 106 + 18x grams of Na₂CO₃ · xH₂O we have 2x grams of hydrogen
then in 100 grams of Na₂CO₃ · xH₂O we have 7.05 grams of hydrogen
106 + 18x = (100 × 2x) / 7.05
106 + 18x = 28.4x
106 = 28.4x - 18x
106 = 10.4x
x = 106 / 10.4
x = 10.2 ≈ 10
The formula for the washing soda is Na₂CO₃ · 10H₂O.
Answer:
The lanthanides and actinides together are sometimes called the inner transition elements.
Explanation:
They are called this because they come up in the periodic table after actinium
Hope this helps :)
Answer: Identical to its parent.
Explanation:
The cloning can be defined as the process by which genetically identical individuals of an organism is produced either artificially or naturally.
The cloning in case of biotechnology refers to the creating the clones of organisms or copies of cells or DNA of the parent cell that is being used in the process.
The parent cell is cloned and numerous copies is made just like that of the asexual reproduction in the nature.
Example: Dolly the sheep.
First, we distinguish whether table sugar or table salt will be more soluble. The bonds between the molecules of the table sugar are weaker than the bonds between the molecules of salt. Therefore, it is easier for the sugar molecules to dissolve.
Next, we evaluate the effect of temperature on solubility. As the temperature of a solvent increases, it is able to hold more and more solute. This means that the sample with table sugar kept at the highest temperature will contain the most dissolved solute, and this is sample 1.
Answer: #2 : s, solid & #3 : PbBr2
Explanation: