Correct Answer: C. substitution

Correct Answer: A) dissolve in alkalis

Explanation

Chlorine, bromine, and iodine are all part of Group 17 in the periodic table, also known as halogens. They share similar chemical properties due to their similar electronic configurations. All halogens have seven electrons in their outermost shell, which gives them a strong tendency to gain one electron to achieve a stable noble gas configuration.

The correct answer isOption A: dissolve in alkalis. Halogens react with alkalis to form salts and water. For example, when chlorine reacts with sodium hydroxide (an alkali), it forms sodium chloride (a salt) and water:

\[{ Cl2 + 2NaOH -> 2NaCl + H2O }\]

This property is common among halogens due to their reactivity and electronegativity. The other options do not correctly describe the similarities among chlorine, bromine, and iodine:

Option B: Not all halogens react violently with hydrogen without heating. Chlorine reacts with hydrogen at room temperature, while bromine and iodine require heating for the reaction to occur.

Option C: They do not displace each other from solutions of their salts. The ability to displace other halogens depends on their reactivity, which decreases down the group. For example, chlorine can displace bromine and iodine, but iodine cannot displace chlorine or bromine.

Option D: They are not all gases. Chlorine is a gas, bromine is a liquid, and iodine is a solid at room temperature.

Option E: They are not all liquids. As mentioned earlier, their physical states differ at room temperature.

In summary, chlorine, bromine, and iodine resemble one another because they all dissolve in alkalis, which is a characteristic property of halogens due to their electronic configurations and reactivity.

Explanation

(a)i. An acid is any compound which in a chemical reaction is able to attach itself to an unshared pair of electrons in another molecule-a base, to form a new compound

ii. - AlCl3

- BF3

- BeF2

- H+

- K+

(b). It is the addition of NaCl to the reaction mixture in soap production to facilitate the precipitation of soap from the mixture

(c) Reagent -- AgNO3 in NH3(aq) / Ammonical silver trioxonitrate

condition-- heat

(d) - It is the fraction of a given isotope in amixture of isotopes of the same element

- The % of an isotope with a specific atomic mass found in a naturally occuring sample of an element.

(e)i. Because the element is

- Unreactive

- Stable

- A noble gas

- Inert

- Completely filled outermost shell

ii. Because of weak forces between the molecules hence not much heat is needed to break the forces

(f) - (Conc) HNO3 produces brown fumes (of NO2) when copper tunings are added to it/copper (II) salt is added but H2SO4 will not react with the copper tuning/Copper (II) salt

- When Conc. H2SO4 is added to sugar it chars the sugar but Conc. HNO3 will not.

- Add BaCl2 solution to each acid white precipitate indicates H2SO4 no precipitate indicates HNO3

(g)

(h) Ionization energy decreases down group 1 elements, the lower the ionization energy, the easier to loose an electron hence the higher the reactive of the elements

(i) Molecular formula shows the actual number of atoms of each element in a molecule

(j) NH3 will deviate more because it has a larger volume and also it has a stronger intermolecular forces

Correct Answer: C) 0.10 mol -3HCI and 5g powdered CaCO3

Correct Answer: B. hardness

Correct Answer: A. Dissolving NH4CI crystals in water

Correct Answer: B) Na2O

Correct Answer: B) CH₂

Explanation

Alkanes are a class of organic compounds consisting of carbon and hydrogen atoms, and they belong to a homologous series. A homologous series is a group of compounds that have the same general formula, similar chemical properties, and show a gradual change in physical properties.

In the case of alkanes, the general formula is C_nH_2n+2. Consecutive members of an alkane homologous series differ by one carbon atom and two hydrogen atoms, which can be represented as CH₂. This is because, as you go down the series, each alkane has one more carbon and two more hydrogen atoms than the previous one.

For example, let's consider three consecutive alkanes: methane (CH₄), ethane (C₂H₆), and propane (C₃H₈). As we move from methane to ethane, we add one carbon atom and two hydrogen atoms (CH₂). The same difference applies when we move from ethane to propane. This pattern continues throughout the alkane series.

Therefore, the correct answer isOption B: CH₂.

Correct Answer: A) 40.0cm³

Correct Answer: B. temperature