As a raindrop falls from a cloud to the surface of Earth,A. its speed increases due to gravity.
B. its speed increases due to air resistance,
C. it moves at a constant speed,
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OD. it moves at a constant velocity

Explanation:

It is known that acidic strength of hydrides of same group tends to increase when we move from top to bottom in a group. On the other hand, acidic strength of hydrides of same period elements increases when we move from left to right in a period.

As both bromine and iodine belongs to the same group. Also, selenium and oxygen are same group elements. Therefore, their acidic strength increases on moving down the group.

Therefore, we can conclude that acidic strength of given compounds from strongest to weakest is as follows.

                HI > HBr > >

Final answer:

To rank the acids in decreasing acid strength using periodic trends, consider the size, electronegativity, and presence of lone pairs of electrons. HI is the strongest acid, followed by HBr, H2O, and H2Se.

Explanation:

To rank the acids in order of decreasing acid strength using periodic trends, we need to consider the size and electronegativity of the atoms. The larger the atom, the weaker the acid, and the more electronegative the atom, the stronger the acid. Additionally, we can consider the presence of lone pairs of electrons, as they increase the acidity.

1. HI - Iodine (I) is larger and less electronegative than the other halogens. It also has a lone pair of electrons, making it the strongest acid.
2. HBr - Bromine (Br) is larger and less electronegative than chlorine (Cl), and it also has a lone pair of electrons. It is the second strongest acid.
3. H2O - Oxygen (O) is smaller and more electronegative than the halogens. It does not have a lone pair of electrons, making it a weaker acid than the halogens.
4. H2Se - Selenium (Se) is larger and less electronegative than sulfur (S). However, it does not have a lone pair of electrons, making it the weakest acid.

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The chemical equation will be;  

(NH4)2S(aq)+SrCl2(aq)→ 2 NH4Cl(aq) + SrSO4(s)

Further Explanation  

Chemical equation  

• A chemical equation is an equation showing chemical symbols of reactants and those of products. They represent a chemical reactions between reactants to form products.
• For example; (NH4)2S(aq)+SrCl2(aq)→ 2 NH4Cl(aq) + SrSO4(s), where (NH4)2S and SrCl2 are reactants while NH4Cl and SrSO4 are products.

Types of chemical reactions  

Precipitation reaction

• Precipitation reactions are reactions which involves the formation of a precipitate as one of the products. A precipitate is a compound that is insoluble in water.
• An example of a precipitation reaction is; (NH4)2S(aq)+SrCl2(aq)→ 2 NH4Cl(aq) + SrSO4(s), where the compound SrSO4 is the precipitate.  

Displacement reaction

• Displacement reactions are reactions where ions replace other ions in their compounds.
• For example; ; (NH4)2S(aq)+SrCl2(aq)→ 2 NH4Cl(aq) + SrSO4(s) is an example of a double displacement reaction where NH4+ takes the place of Sr ions in SrCl2 and Sr2+ takes the place of NH4+ in (NH4)2SO4.

Decomposition reaction  

• Decomposition reactions are reactions which involves break down of a compound to its constituent’s elements or other compounds by use of a catalyst or heat.
• For example; Decomposition of lead (II) nitrate using heat to get lead (ii) oxide, oxygen and nitrogen (IV) oxide.

Neutralization reaction  

• Neutralization reactions are reactions that involve reacting a base or an alkali and an acid to form a salt and water as the only product.

Redox reactions

• Redox reactions are reactions that involve both reduction and oxidation. Some species in reactions undergo reduction while others undergo oxidation.  

Keywords: Chemical reactions, precipitation reactions, chemical equations

Learn more about:

• Types of chemical reactions: brainly.com/question/10038840
• Example of precipitation reaction: brainly.com/question/1146642
• Example of single displacement reaction: brainly.com/question/1146642

Level: High school  

Subject: Chemistry  

Topic: Chemical reactions  

Sub-topic: Precipitation reactions  

Final answer:

No reaction is expected when (NH4)2S(aq) and SrCl2(aq) are mixed, as solubility rules suggest no insoluble salts will form, leading to NOREACTION.

Explanation:

When (NH4)2S(aq) and SrCl2(aq) are mixed together, we expect a reaction where the cations (NH4+ and Sr2+) and anions (S2- and Cl-) exchange partners if any of them can form an insoluble salt. Looking at solubility rules, we know that most sulfides are insoluble except those of alkali metals and ammonium, and most chlorides are soluble except for Ag+, Pb2+, and Hg22+. Given that neither NH4+ nor Sr2+ forms an insoluble chloride and SrS is not listed as an insoluble sulfide, we can predict that no visible reaction will occur when these solutions are mixed. Therefore, the chemical equation to represent this mixture is NOREACTION.

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Answer:

11.29Kj

Explanation:

1. find moles of 33.8g of water

Molar mass of H2O: 18.02g/Mol

33.8/18.02= 1.88mols

2. find energy

1.88 x 6.02= 11.29Kj

Answer:

I think the second space is chemical bonds

Answer:

The factors that govern the position of an IR absorption peak are:

(A) strength of the bond

(C) masses of the atoms involved in the bond

(D) the type of vibration being observed

Explanation:

In infrared spectroscopy the molecules absorb the frequencies that are characteristic of their structure. These absorptions occur at resonance frequencies, that is, the frequency of the absorbed radiation coincides with the frequency of vibration. The energies are affected by the shape of molecular potential energy surfaces, the masses of atoms and the associated vibronic coupling. The resonance frequencies are also related to the strength of the bond and the mass of the atoms at each end of it. Therefore, the frequency of vibrations is associated with a particular normal movement mode and a particular type of link.

Answer:

0.4590

Explanation:

How the refractive index of the hexane + toluene mixture varies linearly with mole fraction, it means that the mole fraction is the fraction that each pure index contribute for the mixture index, so, calling xh the mole fraction of hexane and xt the mole fraction of toluene:

1.375xh + 1.497xt = 1.441

And, xh + xt = 1 (because there are only hexane and toluene in the mixture), so xt = 1- xh

1.375xh + 1.497(1-xh) = 1.441

1.375xh + 1.497 - 1.497xh = 1.441

-0.122xh = -0.056

xh = -0.056/(-0.122)

xh = 0.4590