Answer:
2
Explanation:
Mass of water molecule = mass of hydrated salt - mass of anhydrous salt
Mass of water molecule = 5.00 - 4.26 = 0.74g of water molecule.
Number of moles = mass / molarmass
Molar mass of water = 18.015g/mol
No. of moles of water = 0.74 / 18.015 = 0.0411 moles.
Mass of BaCl2 present =?
1 mole of BaCl2 = 208.23 g
X mole of BaCl2 = 4.26 g
X = (4.26 * 1) / 208.23
X = 0.020
0.020 moles is present in 4.26g of BaCl2
Mole ratio between water and BaCl2 =
0.0411 / 0.020 = 2
Therefore 2 molecules of water is present the hydrated salt.
The correct option is D.
In chemistry, a pure substance refers to a matter that possesses definite and constant composition with unique chemical properties. Another word for a pure substance is chemical substance. A pure substance typically contains only one type of atom or only one type of molecule. Examples of pure substances are water, sodium chloride, gold, silver, etc. In the question given above, we are told that the unknown element can only be broken down by chemical mean, this shows that the unknown compound is a chemical compound.
Answer:
i)
ii)
ii)
Explanation:
As the initial and final states of the sample are the same, the ΔU of the sample is, for the three cases
since
i)Reversibly so can be calculated by
and because of the first law of thermodynamics
ii)Irreversibly with
we can calculate by the law of ideal gases
then w can be calculated by
and
iii)a free expansion so (there's no work at vaccum) and
Explanation:
Molarity = M = mol/1 liter
in sol 250 mL there are KNO3 2.02 mol
in sol 1000 mL there are KNO3 = 2.02/250 × 1000
= 8.08 mol/liter
Chemical change . hope this helps:))))))))