Answer:
b) The dehydrated sample absorbed moisture after heating
Explanation:
a) Strong initial heating caused some of the hydrate sample to splatter out.
This will result in a higher percent of water than the real one, because you assume in the calculation that the splattered sample was only water (which in not true).
b) The dehydrated sample absorbed moisture after heating.
Usually inorganic salts may absorbed moisture from the atmosphere so this will explain the 13% difference between calculated water percent the real content of water in the hydrate.
c) The amount of the hydrate sample used was too small.
It will create some errors but they do not create a difference of 13% difference as stated in the problem.
d) The crucible was not heated to constant mass before use.
Here the error is small.
e) Excess heating caused the dehydrated sample to decompose.
Usually the inorganic compounds are stable in the temperature range of this kind of experiments. If you have an organic compound which retain water molecules you may decompose the sample forming volatile compounds which will leave crucible so the error will be quite high.
Answer:
The elements in the periodic table are arranged in order of increasing atomic number.
Explanation:
A solid dissolves in a liquid when it mixes completely with the liquid. ... Things which dissolve are called solutes and the liquid in which they dissolve is called a solvent to form a solution
Answer:
4KO₂ + 2CO₂ -> 2K₂CO₃ + 3O₂
<u> Step 1: Find the moles of O₂.</u>
n(O₂) = mass/ Mr.
n(O₂) = 100 / 32 = 3.125 mol
<u>Step 2: Find the ratio between KO₂ and O₂.</u>
<u>KO₂ </u> : <u> O₂</u>
4 : 3
4/3 : 1
(4*3125)/3 : 3.125
=4.167 mol of KO₂
Thus now we know, to produce 100 g of O₂, we need 4.167mol of KO₂
<u>Step 3: Find the mass of KO₂:</u>
<u />
mass = mol * Mr. (KO₂)
Mass = 4.167* 71.1
Mass = 296.25 g
Concentration "molarity" of H₂SO₄ in this solution:
5 × 10⁻³ mol / dm³.
<h3>Explanation</h3>
What's the concentration of H⁺ ions in this solution?
,
where
is in the unit mol / dm³.

.
What's the concentration "molarity" of H₂SO₄ in this solution?
Sulfuric acid H₂SO₄ is a strong acid. Note the subscript "2". Each mole of this acid dissolves in water to produce two moles of H⁺ ions. It takes only
of H₂SO₄ to produce twice as much H⁺ ions.
As a result, the <em>molarity</em> of H₂SO₄ is 5 × 10⁻³ mol / dm³ or 0.005 M.