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3 years ago

Can you help me with any of these questions?

Chemistry

1 answer:

icang [17]3 years ago

5 0

Answer:

Question 1:

Answer: Hydronium ions contain a positive charge.

Explanation:

Any ions that formed via losing electrons or giving it to surrounding contain a positive charge that the number of protons is more than that of electrons.

A hydronium ion is represented as (H₃O⁺).

It can be formed via the dissociation of water to form hydronium can be seen here: 2 H₂O ⇌ OH⁻ + H₃O⁺.

It is also can be formed when something like acid (HCl) donates a proton, H+, to a water molecule. The H+ will simply bond to water molecules with one of the two lone pairs of electrons around.

HCl + H₂O → H₃O⁺ + Cl⁻

Question 2:

Answer: Ammonium hydroxide is the best to neutralize sulfuric acid.

Explanation:

Many bases can be used to neutralize sulfuric acid such as NaOH, sodium carbonate, sodium bicarbonate, calcium hydroxide, ammonium hydroxide, …etc.

Ammonium hydroxide is one of the best choices to neutralize sulfuric acid because it is not strong base. Also, ammonium compounds are soluble in water, so no color change, and no precipitate will be observed.

The neutralization reaction between ammonium hydroxide and sulfuric acid: 2 NH₄OH + H₂SO₄ ⟶ (NH₄)₂SO₄ + 2 H₂O.

Question 3:

Answer: Raisins in cereals are example of heterogeneous mixture.

Explanation:

Heterogeneous mixture is the mixture that is not uniform in composition and properties. We can identify and see the different components in the mixture.

Raisins are the dried fruit of a certain type grape and they are different and can not be mixed in cereals to be homogeneous, so raisins in cereals are example of heterogeneous mixture.

Question 4:

Answer: Sugar dissolves in water because both are made up of polar molecules.

Explanation:

We have a rule that “like dissolves like”. Polar molecules dissolve the polar salts and non-polar molecules dissolves the non-polar type.

Sugar is polar molecules that contains in its structure C-O-H. They have difference in electronegativity that make it forms hydrogen bonds between its molecules and thus dissolves in the polar solvent water.

Question 5:

Answer: Steel is an alloy.

Explanation:

Alloy can be defined as a combination of adding two or more metals or components to enhance its physical properties and its overall performance that of each single metal or component forming the alloy.

Steel is an alloy composed of iron (the main component) and carbon (sometimes using phosphorus, silicon, manganese, chromium, …etc.) in very little proportion. It is characterized by its high tensile strength and low cost.

So, it is widely used in buildings, infrastructure, tools, ships, automobiles, machines, appliances, and weapons.

Kindly find the answers of the remaining questions in the attached images.

Image 1 (Q6: Q9)

Image 2 (Q10: Q12)

Image 3 (Q13: Q16)

Image 4 (Q17: Q20)

Image 5 (Q21: Q24)

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What happens after excitation in spectroscopy.

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Answer:

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This table has information about the heat of fusion and the heat of vaporization of different substances. A 3-column table with

blagie [28]

H₂S

<h3>Further explanation</h3>

Given

ΔH fusion and ΔH vaporization of different substances

Required

The substance absorbs 58.16 kJ of energy when 3.11 mol vaporizes

Solution

We can use the formula :

$\tt \Delta H=\dfrac{Q}{n}$

Q=heat/energy absorbed

n = moles

The heat absorbed : 58.16 kJ

moles = 3.11

so ΔH vaporization :

$\tt \Delta H_{vap}=\dfrac{58.16~kJ}{3.11~mol}\\\\\Delta H_{vap}=18.7~kJ/mol$

The correct substance which has ΔH vaporization = 18.7 kj / mol is H₂S

(H₂S from the data above has ΔH fusion = 2.37 kj / mol and ΔH vaporization = 18.7 kj / mol)

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Read 2 more answers

How many moles are in 12 liters of Cl2?

RoseWind [281]

Answer:

$\boxed {\boxed {\sf 0.54 \ mol \ Cl_2}}$

Explanation:

A mole is any quantity of a substance that contains 6.02 × 10²³ particles. At standard temperature and pressure, or STP, 1 mole of as is equal to 22.4 liters. This is true for any gas, regardless of the specific kind.

Although it is not specified, we can assume this gas is at STP. Let's set up a ratio using this information: 22.4 L/mol

$\frac {22.4 \ L \ Cl_2}{1 \ mol \ Cl_2}$

Multiply by the given number of liters: 12

$12 \ L \ Cl_2 *\frac {22.4 \ L \ Cl_2}{1 \ mol \ Cl_2}$

Flip the ratio so the liters of chlorine cancel.

$12 \ L \ Cl_2 * \frac {1 \ mol \ Cl_2}{22.4 \ L \ Cl_2}$

$12 * \frac {1 \ mol \ Cl_2}{22.4 }$

$\frac {12}{22.4 } \ mol \ Cl_2$

$0.53571428571 \ mol \ Cl_2$

The original measurement of liters has 2 significant figures, so our answer must have the same.

For the number we found, that is the hundredth place.

0.53571428571

The 5 in the thousandth place tells us to round the 3 up to a 4.

$0.54 \ mol \ Cl_2$

12 liters of chlorine gas at STP is approximately 0.54 moles of chlorine gas.

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