# 18.1 Periodicity  (Page 8/16)

 Page 8 / 16

## Chemistry end of chapter exercises

How do alkali metals differ from alkaline earth metals in atomic structure and general properties?

The alkali metals all have a single s electron in their outermost shell. In contrast, the alkaline earth metals have a completed s subshell in their outermost shell. In general, the alkali metals react faster and are more reactive than the corresponding alkaline earth metals in the same period.

Why does the reactivity of the alkali metals decrease from cesium to lithium?

Predict the formulas for the nine compounds that may form when each species in column 1 of [link] reacts with each species in column 2.

1 2
Na I
Sr Se
Al O

$\begin{array}{l}\text{Na}+{\text{I}}_{2}\phantom{\rule{0.2em}{0ex}}⟶\phantom{\rule{0.2em}{0ex}}\text{2NaI}\\ \text{2Na}+\text{Se}\phantom{\rule{0.2em}{0ex}}⟶\phantom{\rule{0.2em}{0ex}}{\text{Na}}_{2}\text{Se}\\ \text{2Na}+{\text{O}}_{2}\phantom{\rule{0.2em}{0ex}}⟶\phantom{\rule{0.2em}{0ex}}{\text{Na}}_{2}{\text{O}}_{2}\end{array}$
$\begin{array}{l}\text{Sr}+{\text{I}}_{2}\phantom{\rule{0.2em}{0ex}}⟶\phantom{\rule{0.2em}{0ex}}{\text{SrI}}_{2}\\ \text{Sr}+\text{Se}\phantom{\rule{0.2em}{0ex}}⟶\phantom{\rule{0.2em}{0ex}}\text{SrSe}\\ \text{2Sr}+{\text{O}}_{2}\phantom{\rule{0.2em}{0ex}}⟶\phantom{\rule{0.2em}{0ex}}\text{2SrO}\end{array}$
$\begin{array}{l}\text{2Al}+{\text{3I}}_{2}\phantom{\rule{0.2em}{0ex}}⟶\phantom{\rule{0.2em}{0ex}}{\text{2AlI}}_{3}\\ \text{2Al}+\text{3Se}\phantom{\rule{0.2em}{0ex}}⟶\phantom{\rule{0.2em}{0ex}}{\text{Al}}_{2}{\text{Se}}_{3}\\ \text{4Al}+{\text{3O}}_{2}\phantom{\rule{0.2em}{0ex}}⟶\phantom{\rule{0.2em}{0ex}}{\text{2Al}}_{2}{\text{O}}_{3}\end{array}$

Predict the best choice in each of the following. You may wish to review the chapter on electronic structure for relevant examples.

(a) the most metallic of the elements Al, Be, and Ba

(b) the most covalent of the compounds NaCl, CaCl 2 , and BeCl 2

(c) the lowest first ionization energy among the elements Rb, K, and Li

(d) the smallest among Al, Al + , and Al 3+

(e) the largest among Cs + , Ba 2+ , and Xe

Sodium chloride and strontium chloride are both white solids. How could you distinguish one from the other?

The possible ways of distinguishing between the two include infrared spectroscopy by comparison of known compounds, a flame test that gives the characteristic yellow color for sodium (strontium has a red flame), or comparison of their solubilities in water. At 20 °C, NaCl dissolves to the extent of $\frac{\text{35.7 g}}{\text{100 mL}}$ compared with $\frac{\text{53.8 g}}{\text{100 mL}}$ for SrCl 2 . Heating to 100 °C provides an easy test, since the solubility of NaCl is $\frac{\text{39.12 g}}{\text{100 mL}},$ but that of SrCl 2 is $\frac{\text{100.8 g}}{\text{100 mL}}.$ Density determination on a solid is sometimes difficult, but there is enough difference (2.165 g/mL NaCl and 3.052 g/mL SrCl 2 ) that this method would be viable and perhaps the easiest and least expensive test to perform.

The reaction of quicklime, CaO, with water produces slaked lime, Ca(OH) 2 , which is widely used in the construction industry to make mortar and plaster. The reaction of quicklime and water is highly exothermic:
$\text{CaO}\left(s\right)+{\text{H}}_{2}\text{O}\left(l\right)\phantom{\rule{0.2em}{0ex}}⟶\phantom{\rule{0.2em}{0ex}}\text{Ca}{\left(\text{OH}\right)}_{2}\left(s\right)\phantom{\rule{3em}{0ex}}\text{Δ}H=\text{−350 kJ}\phantom{\rule{0.2em}{0ex}}{\text{mol}}^{\text{−1}}$

(a) What is the enthalpy of reaction per gram of quicklime that reacts?

(b) How much heat, in kilojoules, is associated with the production of 1 ton of slaked lime?

Write a balanced equation for the reaction of elemental strontium with each of the following:

(a) oxygen

(b) hydrogen bromide

(c) hydrogen

(d) phosphorus

(e) water

(a) $\text{2Sr}\left(s\right)+{\text{O}}_{2}\left(g\right)\phantom{\rule{0.2em}{0ex}}⟶\phantom{\rule{0.2em}{0ex}}\text{2SrO}\left(s\right);$ (b) $\text{Sr}\left(s\right)+\text{2HBr}\left(g\right)\phantom{\rule{0.2em}{0ex}}⟶\phantom{\rule{0.2em}{0ex}}{\text{SrBr}}_{2}\left(s\right)+{\text{H}}_{2}\left(g\right);$ (c) $\text{Sr}\left(s\right)+{\text{H}}_{2}\left(g\right)\phantom{\rule{0.2em}{0ex}}⟶\phantom{\rule{0.2em}{0ex}}{\text{SrH}}_{2}\left(s\right);$ (d) $\text{6Sr}\left(s\right)+{\text{P}}_{4}\left(s\right)\phantom{\rule{0.2em}{0ex}}⟶\phantom{\rule{0.2em}{0ex}}{\text{2Sr}}_{3}{\text{P}}_{2}\left(s\right);$ (e) $\text{Sr}\left(s\right)+{\text{2H}}_{2}\text{O}\left(l\right)\phantom{\rule{0.2em}{0ex}}⟶\phantom{\rule{0.2em}{0ex}}\text{Sr}{\left(\text{OH}\right)}_{2}\left(aq\right)+{\text{H}}_{2}\left(g\right)$

How many moles of ionic species are present in 1.0 L of a solution marked 1.0 M mercury(I) nitrate?

What is the mass of fish, in kilograms, that one would have to consume to obtain a fatal dose of mercury, if the fish contains 30 parts per million of mercury by weight? (Assume that all the mercury from the fish ends up as mercury(II) chloride in the body and that a fatal dose is 0.20 g of HgCl 2 .) How many pounds of fish is this?

11 lb

The elements sodium, aluminum, and chlorine are in the same period.

(a) Which has the greatest electronegativity?

(b) Which of the atoms is smallest?

(c) Write the Lewis structure for the simplest covalent compound that can form between aluminum and chlorine.

(d) Will the oxide of each element be acidic, basic, or amphoteric?

Does metallic tin react with HCl?

Yes, tin reacts with hydrochloric acid to produce hydrogen gas.

What is tin pest, also known as tin disease?

Compare the nature of the bonds in PbCl 2 to that of the bonds in PbCl 4 .

In PbCl 2 , the bonding is ionic, as indicated by its melting point of 501 °C. In PbCl 4 , the bonding is covalent, as evidenced by it being an unstable liquid at room temperature.

Is the reaction of rubidium with water more or less vigorous than that of sodium? How does the rate of reaction of magnesium compare?

Whats d IUPAC Numenclature of bromine
The common name is therefore propyl bromide . For the IUPAC name , the prefix for bromine (bromo) is combined with the name for a three-carbon chain (propane), preceded by a number identifying the carbon atom to which the Br atom is attached, so the IUPAC name is 1-bromopropane.
crystal
What is Quantum number
what are the chemical properties of group IIA Element and their atomic structure?
What is mixture
A mixture is a mix of substances that can be separated
Lillie
what is quantum number
Hmm
kedis
I suck at chemistry I need a tutor
kedis
h20 hydrates, nitrogen/dry ice lowers pressure similar to space environment when heated at what location/temp.? +or-, expect location (xyz)
Brian
hey kedis,never say that u suck,u don't,all u need is to calm down,get the book and get the points,no need to read it word by word or a-z. ur good bro,u r veeeery intelligent
UDUJI
awwwww
Cereal
what's neuron?
neuron or neutron?
John
cell of the nerve
Kamaluddeen
prepare a solution of 1m iodine in 250mls of water
Really
Wisdom
Hiiii am new here
Wisdom
Really
Wisdom
WHAT IS CHEMISTRY?
RJ
Chemistry is the study of matter
Wisdom
chemistry is the study of matter and changes it undergoes
Mercy
what is equilibrium
what is biology
Fatai
biology is said to be the science of studying life and living organism including theirs physical structure,chemical processes, molecular interaction development and evolution
David
atomic number of sodium
bose
that'll be 11
Kamaluddeen
ok
bose
anymore questions 😁
Franklin
re u writing jamb
bose
please, how man Bond are present when a methane under goes a complete combustion
Combustion of Methane The reactants are on the left side of the equation and the products are on the right. In the reaction, the bonds in the methane and oxygen come apart, the atoms rearrange and then re-bond to form water and carbon dioxide.
saidi
how is ethanol produced using ethene
Glory
Ethanol is manufactured by reacting ethene with steam. The reaction is reversible, and the formation of the ethanol is exothermic. Only 5% of the ethene is converted intoethanol at each pass through the reactor
saidi
Ethanol can be made by reacting ethene (from cracking crude oil fractions) with steam. A catalyst of phosphoric acid is used to ensure a fast reaction. Notice that ethanol is the only product. The process is continuous – as long as ethene and steam are fed into one end of the reaction vessel, ethano
saidi
the mole concerpt and its tricks
what are atoms
the individual elements of matter.
Reginald
tiny particles that make up a all matter.
Reginald
smallest particles of an element
Osuji
What is the meaning of hybridization
Differentiate between latent heat and specific latent heat of fusion and vaporization
Ans: The amount of heat energy released or absorbed when a solid changing to liquid at atmospheric pressure at its melting point is known as the latent heat of fusion. while Vaporization of an element or compound is a phase transition from the liquid phase to vapor.
Acquah
a student was required to prepare 500cm of 1.0M solution of glucose(C6H12O6). (C=12, H=1, O=16).determine a.molar mass of glucose b.amount of glucose in mole c.mass of glucose contained in the solution
Mac
what are ionic compound