All categories

3 years ago

Find out the reasons why hydrogen is not used as a fuel although it has very high calorific value.

Chemistry

1 answer:

AnnyKZ [126]3 years ago

3 0

Answer:

Although hydrogen has the highest calorific value, it is not used as a domestic fuel. It is because hydrogen is a highly combustible and it reacts explosively when it comes in contact with air. And hence as a result, storing of the hydrogen gas is difficult and is dangerous at the same time.

You might be interested in

Classify each element. Note that another term for main group is representative, another term for semimetal is metalloid, and the

NikAS [45]

The question is incomplete, here is the complete question:

Classify each element. Note that another term for main group is representative, another term for semi-metal is metalloid, and the inner transition metals are also called the lanthanide and actinide series.

Hf, Am, In, Ta, As, Se, Rn

Answer:

Hafnium and tantalum are transition elements.

Americium is a inner transition element.

Indium, Selenium and Radon are main group elements.

Arsenic is a metalloid.

Explanation:

Main group elements are the elements which belong to s block and p block. They are also known as representative elements.

S-block elements are defined as the elements whose last electron enters s-sub shell. The general electronic configuration of these elements is $ns^{1-2}$

P-block elements are defined as the elements whose last electron enters p-sub shell. The general electronic configuration of these elements is $np^{1-6}$

Metalloids are defined as the elements which show intermediate properties between metals and non-metals. There are 7 metalloids in the periodic table. They are: Boron, Silicon, germanium, Arsenic, Antimony, Tellurium and Polonium.

Transition elements are known as d-block elements. D block elements are defined as the elements whose last electron enters d sub shell. The general electronic configuration of these elements is $[(n-1)d^{1-10}ns^{0-2}]$

Inner transition elements are known as (f block) elements. (F block) elements are defined as the elements whose last electron enters (f subshell). The general electronic configuration of these elements is $[(n-2)f^{1-14}(n-1)d^{0-1}ns^{2}]$ . They are also known as lanthanide and actinide series.

For the given elements:

Option 1: Hf

Hafnium is the 72nd element of the periodic table having electronic configuration of $[Xe]4f^{14}5d^26s^2$

As, the last electron is entering the d subshell, it is a transition element.

Option 2: Am

Americium is the 95th element of the periodic table having electronic configuration of $[Rn]5f^{7}6d^07s^2$

As, the last electron is entering the (f subshell), it is a inner transition element.

Option 3: In

Indium is the 49th element of the periodic table having electronic configuration of $[Kr]5s^25p^1$

As, the last electron is entering the p subshell, it is a main group element.

Option 4: Ta

Tantalum is the 73rd element of the periodic table having electronic configuration of $[Xe]4f^{14}5d^56s^2$

As, the last electron is entering the d subshell, it is a transition element.

Option 5: As

Arsenic is the 33rd element of the periodic table having electronic configuration of $[Ar]4s^24p^3$

As, the last electron is entering the p subshell, it is a main group element. It shows an intermediate property of metal and non-metal. Thus, it is a metalloid.

Option 6: Se

Selenium is the 34th element of the periodic table having electronic configuration of $[Ar]4s^24p^4$

As, the last electron is entering the p subshell, it is a main group element.

Option 7: Rn

Radon is the 86th element of the periodic table having electronic configuration of $[Xe]4f^{14}5d^{10}6s^26p^6$

As, the last electron is entering the p subshell, it is a main group element.

5 0

3 years ago

An ionic bond involves the.....

Svetllana [295]

Ionic bonding is a type of chemical bonding that involves the electrostatic attraction between oppositely charged ions, or between two atoms with sharply different electronegativities, and is the primary interaction occurring in ionic compounds

5 0

3 years ago

Read 2 more answers

How is a lithium atom (Li) different from a lithium ion (Li+)

UkoKoshka [18]

Answer:

(Li) has fewer electrons than (Li+)

3 0

3 years ago

2zns(s)+3o2(g)—>2zno(s)+2so2(g)

Paha777 [63]

This is an example of displacement reaction

Explanation:

The chemical reaction in which the one element replaces the other element in a compound is called a displacement reaction. This reaction is also called a replacement reaction.

AB + C -----> AC +B

2ZnS + 3O2 -----> 2ZnO + 2SO2

This happens when A is more reactive than B and gives a stable product. Here the zinc sulfide compound reacts with the oxygen element to the stable product of zinc oxide and sulfur dioxide.

In short, the more reactive element displaces the less reactive element is called a displacement reaction.

8 0

3 years ago

g The reaction; 4 Ag(s) + O2(g) ----> 2 Ag2O(s), is exothermic. Which statement about the reaction is correct? (A) It is spon

melomori [17]

Answer:

The correct answer is B. It is spontaneous only at low temperatures.

Explanation:

In thermodynamics, the Gibbs free energy is a thermodynamic potential that can be used to calculate the maximum of reversible work that may be performed by a thermodynamic system at a constant temperature and pressure.

The spontaneity of a reaction is given by the equation:

ΔG = ΔH - TΔS

where:

ΔH: enthalpy variation

T: absolute temperature

ΔS: entropy variation

As the reaction is exothermic, ΔH<0

As the reaction order increases (the reagents are solid and gas and their product is solid), ΔS<0

Therefore, the reaction will be spontaneous when ΔG is negative.

ΔG = ΔH - TΔS

That is, the entropy term must be smaller than the enthalpy term.

Hence, the reaction will be spontaneous only at low temperatures.

4 0

3 years ago