Answer:
to make a discovery, test a hypothesis, or demonstrate a known fact.
Explanation:
perform a scientific procedure, especially in a laboratory, to determine something.
Answer:
Mass in an isolated system can neither be destroyed nor created.
Explanation:
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:
100 ml = 0.1 L
I divided 100 by 1000 because 1000ml = 1L
Answer: B. Elements are represented by chemical formulas.
Elements are pure substances, which means that they cannot be broken down into simpler substances. The element is the most basic substance that exists, breaking it down further means breaking it down into protons, neutrons, and electrons, which is no longer a substance.
Elements have chemical properties that allow them to form different types of bonds with other elements.
However, elements *alone* are not represented by their chemical formulas. Only chemical bonds or ions are represented by a chemical formula.
