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3 years ago

What is the boiling point of water at standard atmospheric pressure?

Chemistry

1 answer:

denis23 [38]3 years ago

6 0

Answer:100c

Explanation:

water boils at 100c the normal boiling point is the temperature at which the vapour pressure is equal to the standard sea-level atmospheric pressure

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suppose you want to treat if a sample compound is ionic. you have these materials: the solid compound, a glass container, a spoo

xz_007 [3.2K]

An ionic compound is a substance that contains atoms that are bonded together through an ionic bond, where electrons are transferred from one atom to another. For the given experiment above, the material that is missing from the list is WATER or solvent. It is necessary because conduction through water will help you identify if a sample compound is ionic through its electrolytes. Ionic compounds that are soluble are typically electrolytes

6 0

3 years ago

Read 2 more answers

A buffer solution contains 0.479 M NaHCO3 and 0.342 M Na2CO3. Determine the pH change when 0.091 mol HNO3 is added to 1.00 L of

pshichka [43]

Answer:

ΔpH = 0.20

Explanation:

The buffer of HCO₃⁻ + CO₃²⁻ has a pka of 10.2

HCO₃⁻ ⇄ H⁺ + CO₃²⁻

There are 0.479moles of NaHCO₃ and 0.342moles of Na₂CO₃.

Using Henderson-Hasselbalch formula:

pH = pka + log [Base] / [Acid]

pH = 10.2 + log 0.342mol / 0.479mol

pH = 10.05

NaOH reacts with HCO₃⁻ producing CO₃²⁻, thus:

NaOH + HCO₃⁻ → CO₃²⁻ + H₂O + Na⁺

0.091 moles of NaOH produce the same moles of CO₃²⁻ and consume HCO₃⁻. Moles of these species are:

CO₃²⁻: 0.342mol + 0.091mol: 0.433mol

HCO₃⁻: 0.479mol - 0.091 mol: 0.388mol

Using Henderson-Hasselbalch formula:

pH = pka + log [Base] / [Acid]

pH = 10.2 + log 0.433mol / 0.388mol

pH = 10.25

That means change of pH, ΔpH is:

ΔpH = 10.25 - 10.05 = 0.20

I hope it helps!

3 0

3 years ago

What is the mass of an atom that has 9 protons, 11 neutrons, and 10 electrons

Anastaziya [24]

Answer: By looking at the periodic table, you will see that Fluorine has 9 protons. Since the number of electrons equal the number of protons, Fluorine has 9 electrons as well. Meanwhile, it's mass number of 19, minus 10 neutrons, gives you 9 protons or electrons. Hence, the atom would be Fluorine.

Explanation:

6 0

3 years ago

Read 2 more answers

A solution is initially 0.10m in mg2+(aq) and 0.10m in fe2+(aq). solid naoh is slowly added. what is the concentration of fe2+ w

dexar [7]

Mg(OH)₂ ⇄ Mg²⁺ + 2 OH⁻

Ksp = [Mg²⁺] [OH⁻]²

6.0 x 10⁻¹⁰ = 0.10 x [OH⁻]²

[OH⁻] = 7.746 x 10⁻⁵ M

when Mg(OH)₂ 1st precipitates, [OH⁻] = 7.746 * 10⁻⁵ M

Fe(OH)₂ <—> Fe²⁺ + 2OH⁻

Ksp = [Fe²⁺] [OH⁻]²

7.9 x 10⁻¹⁶ = [Fe²⁺] x (7.746 x 10⁻⁵)²

[Fe²⁺] = 1.32 x 10⁻⁷ M

Answer: 1.32 x 10⁻⁷ M

5 0

3 years ago

According to atomic theory:

JulsSmile [24]

Answer:

e. all of these

Explanation:

Let us check all the given options one by one:

a.The nucleus is positively charged.

Yes it is correct since nucleus contain protons and neutrons and protons are positively charged.

b.The nucleus contains both charged and uncharged particles.

Yes because protons are positively charged and neutrons are neutral in nature.

c.The electrons contribute very little to the total mass of the atom.

Yes we know all the mass of the atom is considered in center and mass of electron is negligible as compared to protons and neutrons.

d.The electrons are located in the atomic space outside the nucleus.

Yes, its a known fact.

e. All of these.

Since , all given options are correct .

Therefore , option e. is right .

7 0

3 years ago