Some people weren't convinced with the theory. Also many people tried to prove that the atom didn't exist, or at least prove the theory wrong.
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:
<h2>Density = 0.75 g/mL</h2>
Explanation:
The density of a substance can be found by using the formula
From the question
mass = 450 g
volume = 6.0 × 10² mL
Substitute the values into the above formula and solve for the density
That's
We have the final answer as
<h3>Density = 0.75 g/mL</h3>
Hope this helps you
Explanation:
Crystals often form in nature when liquids cool and start to harden. Certain molecules in the liquid gather together as they attempt to become stable. They do this in a uniform and repeating pattern that forms the crystal. In nature, crystals can form when liquid rock, called magma, cools.
Answer:
0.875 moles solute
Explanation:
You can find the moles of the solute using the molality ratio:
Molality = moles solute / mass (kg) solution
After converting the mass to kilograms, you can plug the values into the ratio and simplify to find the moles.
1,000 g = 1 kg
350 g 1 kg
-------------- x --------------- = 0.35 kg solution
1,000 g
Molality = moles solute / mass solution
2.5 m = moles solute / 0.35 kg
0.875 = moles solute
