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2 years ago

The text of oxygen gas in the laboratory

Chemistry

1 answer:

IgorC [24]2 years ago

8 0

Explanation:in testing for oxygen a glowing splint is used.

the glowing splint is brought in the presence of the test tube containing the gas

the glowing splint rekindles or lights up showing that oxygen is present.

this is a positive test because oxygen supports burning or combustion

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Write the balanced chemical equation between H2SO4H2SO4 and KOHKOH in aqueous solution. This is called a neutralization reaction

const2013 [10]

Answer:

0.185M sulfuric acid

Explanation:

Based on the reaction:

H₂SO₄ + 2KOH → K₂SO₄ + 2H₂O

1 mole of sulfuric acid reacts with 2 moles of KOH

Initial moles of H₂SO₄ and KOH are:

H₂SO₄: 0.750L ₓ (0.470mol / L) = 0.3525 moles of H₂SO₄

KOH: 0.700L ₓ (0.240mol / L) = 0.168 moles of KOH

The moles of sulfuric acis that react with KOH are:

0.168mol KOH ₓ (1 mole H₂SO₄ / 2 moles KOH) = 0.0840 moles of sulfuric acid.

Thus, moles that remain are:

0.3525moles - 0.0840 moles = 0.2685 moles of sulfuric acid remains

As total volume is 0.700L + 0.750L = 1.450L, concentration is:

0.2685mol / 1.450L = 0.185M sulfuric acid

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2 years ago

An atom's Lewis dot structure has four dots. Which of the following elements could it be, and why?

Elis [28]

Answer:

Beryllium, because it is in period 2 and has four total electrons.

Explanation:

7 0

2 years ago

How many moles of CO2 must dissolve in excess water to produce 12 moles of H2CO3?

vodka [1.7K]

Answer:

12 moles of CO₂.

Explanation:

We'll begin by writing the balanced equation for the reaction. This is illustrated below:

CO₂ + H₂O —> H₂CO₃

From the balanced equation above,

1 mole of CO₂ dissolves in water to produce 1 mole of H₂CO₃.

Finally, we shall determine the number of moles of CO₂ that will dissolve in water to produce 12 moles of H₂CO₃. This can be obtained as follow:

From the balanced equation above,

1 mole of CO₂ dissolves in water to produce 1 mole of H₂CO₃.

Therefore, 12 moles of CO₂ will also dissolve in water to produce 12 moles of H₂CO₃.

Thus, 12 moles of CO₂ is required.

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2 years ago

Plz answer this question.....I know the answer for this question but I want to know the explanation plz plz plz I want to know t

vlabodo [156]

The compound $C_{3}H_{4}$ will have a triple bond.

Explanation:

A compound which consists of carbon and hydrogen atoms is known as a hydrocarbon.

Alkanes, alkenes and alkynes are all hydrocarbons.

General chemical formula of an alkane is $C_{n}H_{2n+2}$ . In an alkane molecule, all the atoms will be bonded through single bonds.

For example, $C_{3}H_{8}$ is propane.

General chemical formula of an alkene is $C_{n}H_{2n}$ . An alkene molecule will have atleast one double bond between two carbon atoms.

For example, $C_{2}H_{4}$ is ethene.

General chemical formula of an alkyne is $C_{n}H_{2n-2}$ . An alkyne will have atleast one triple bond between two carbon atoms.

For example, $C_{3}H_{4}$ is propyne.

Thus, we can conclude that out of the given options $C_{3}H_{4}$ will have a triple bond.

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2 years ago

Calculate the pH in titration of a weak acid: What is the pH in titration of formic acid (HCHO2, 0.200 M, 100.0 mL) after the ad

ki77a [65]

Answer:

pH = 12.61

Explanation:

First of all, we determine, the milimoles of base:

0.120 M = mmoles / 300 mL

mmoles = 300 mL . 0120 M = 36 mmoles

Now, we determine the milimoles of acid:

0.200 M = mmoles / 100 mL

mmoles = 100 mL . 0.200M = 20 mmoles

This is the neutralization:

HCOOH + OH⁻ ⇄ HCOO⁻ + H₂O

20 mmol 36 mmol 20 mmol

16 mmol

We have an excess of OH⁻, the ones from the NaOH and the ones that formed the salt NaHCOO, because this salt has this hydrolisis:

NaHCOO → Na⁺ + HCOO⁻

HCOO⁻ + H₂O ⇄ HCOOH + OH⁻ Kb → Kw / Ka = 5.55×10⁻¹¹

These contribution of OH⁻ to the solution is insignificant because the Kb is very small

So: [OH⁻] = 16 mmol / 400 mL → 0.04 M

- log [OH⁻] = pOH → 1.39

pH = 14 - pOH → 12.61

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2 years ago

The text of oxygen gas in the laboratory ​

The text of oxygen gas in the laboratory