All categories

2 years ago

Why melting and boiling points can be used as a way to check purity?

Chemistry

1 answer:

jekas [21]2 years ago

6 0

Answer: Let's see why

Pure solid and liquid compounds possess sharp melting and boiling points. Therefore, melting and boiling points of a compound can be used as a criteria of purity. ... Sometimes during cooling minute quantity of the substance (solid which is being purified) is added to the solution to facilitate the initial crystallisation.

Explanation:

You might be interested in

How many atoms are in 15.0 moles of C2H6O

Burka [1]

1 mole = 6.22 x 10^23 molecules (Avogadro's number)
15 moles x (6.22 x 10^23) = 9.33 x 10^24 atoms

3 0

3 years ago

Read 2 more answers

Which processes occur when energy is removed from a substance

ratelena [41]

Answer:

Note that melting and vaporization are endothermic processes in that they absorb or require energy, while freezing and condensation are exothermic process as they release energy.

8 0

2 years ago

Hydrogen sulfide decomposes according to the following reaction: 2H2S(g) ⇋ 2H2(g) + S2(g) Kc=9.30x10-8 at 700.°C.If 0.45 mol of

Natalija [7]

Answer:

[H₂] = 1.61x10⁻³ M

Explanation:

2H₂S(g) ⇋ 2H₂(g) + S₂(g)

Kc = 9.30x10⁻⁸ = $\frac{[H_{2}]^2[S_{2}]}{[H_{2}S]^2}$

First we calculate the initial concentration:

0.45 molH₂S / 3.0L = 0.15 M

The concentrations at equilibrium would be:

[H₂S] = 0.15 - 2x

[H₂] = 2x

[S₂] = x

We put the data in the Kc expression and solve for x:

$\frac{(2x^2) * x}{(0.15-2x)^2}=9.30x10^{-8}$

$\frac{4x^3}{0.0225-4x^2}=9.30*10^{-8}$

We make a simplification because x<<< 0.0225:

$\frac{4x^3}{0.0225} =9.30*10^{-8}$

x = 8.058x10⁻⁴

[H₂] = 2*x = 1.61x10⁻³ M

5 0

3 years ago

Read 2 more answers

How many milliliters of a 1.5 m h2so4 are needed to neutralize 35ml sample of a 1.5 m solution?

DochEvi [55]

Answer:

1) 17.5 mL

Explanation:

Hello,

In this case, the reaction between sulfuric acid and potassium hydroxide is:

$H_2SO_4+2KOH\rightarrow K_2SO_4+2H_2O$

In such a way, we notice a 1:2 molar ratio between the acid and the base, therefore, at the equivalence point we have:

$2*n_{acid}=n_{base}$

And in terms of concentrations and volumes:

$2*M_{acid}V_{acid}=M_{base}V_{base}$

Thus, we solve for the volume of acid:

$V_{acid}=\frac{M_{base}V_{base}}{2*M_{acid}} =\frac{35mL*1.5M}{2*1.5M} \\\\V_{acid}=17.5mL$

Best regards.

5 0

3 years ago

Which scientist discovered that the atomic number, rather than the atomic weight, is more responsible for the properties of an e

myrzilka [38]

Answer:

The correct option is Moseley who has discovered the atomic number.

Explanation:

In 1913, H. Moseley discovered a new properties of an element atomic number. He observed that elements in the periodic table can be arranged better according to atomic number rather than atomic mass.
The atomic number of any elements is always equal to numbers of electrons in it.

3 0

3 years ago

Why melting and boiling points can be used as a way to check purity?​

Why melting and boiling points can be used as a way to check purity?