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3 years ago

A chemical change has occured if the number of atoms is greater after the reaction than it was before the reaction.

Chemistry

1 answer:

diamong [38]3 years ago

8 0

Answer:

False

Explanation:

It is not correct to assert that a chemical change has occurred if the number of atoms is greater after the reaction than it was before the reaction.

For every chemical reaction, the law of conservation of mass must be strictly adhered.

The law states that "during a chemical reaction, matter is neither created nor destroyed, atoms are simply rearranged".

By the virtue of this law, the number of atoms at the beginning and the end of the reaction must remain the same for this law to be applicable.

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A bond in which one atom contributes both bonding electrons to a covalentbond

yKpoI14uk [10]

<h3>Answer:</h3>

A coordinate bond

<h3>Explanation:</h3>

A chemical bond is a force of attraction between two or more atoms of elements.
Covalent bond is a type of chemical bond that occurs between non-metal atoms.
It occurs as a result of sharing of electrons between the non-metal atoms.
Atoms involved in covalent bond formation may contribute equally to the bond formation or the electrons shared may come form one of the atoms.
When the electrons shared in a covalent bond are derived from one atom, then the covalent bond is known as a coordinate bond.

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3 years ago

How many protons electrons and neutrons does the following isotopes contain 1H+

Rus_ich [418]

Answer: 1 proton, 0 electron and 1 neutron are present in 1 H⁺ isotope.

8 0

3 years ago

Which of the following reactions could be an elementary reaction? 2 NO2(g) + F2(g) → 2NO2F(g) Rate = k[NO2][F2] H2(g) + Br2(g) →

podryga [215]

<u>Answer:</u> The correct answer is $NO(g)+O_2(g)\rightarrow NO_2(g)+O(g);Rate=k[NO][O_2]$

<u>Explanation:</u>

Molecularity of the reaction is defined as the number of atoms, ions or molecules that must colloid with one another simultaneously so as to result into a chemical reaction.

Order of the reaction is defined as the sum of the concentration of terms on which the rate of the reaction actually depends. It is the sum of the exponents of the molar concentration in the rate law expression.

Elementary reactions are defined as the reactions for which the order of the reaction is same as its molecularity and order with respect to each reactant is equal to its stoichiometric coefficient as represented in the balanced chemical reaction.

For the given reactions:

<u>Equation 1:</u> $2NO_2(g)+F_2(g)\rightarrow 2NO_2F(g);Rate=k[NO_2][F_2]$

Molecularity of the reaction = 2 + 1 = 3

Order of the reaction = 1 + 1 = 2

This is not considered as an elementary reaction.

<u>Equation 2:</u> $H_2(g)+Br_2(g)\rightarrow 2HBr(g);Rate=k[H_2][Br_2]^{1/2}$

Molecularity of the reaction = 1 + 1 = 2

Order of the reaction = $1+\frac{1}{2}=\frac{3}{2}$

This is not considered as an elementary reaction.

<u>Equation 3:</u> $NO(g)+O_2(g)\rightarrow NO_2(g)+O(g);Rate=k[NO][O_2]$

Molecularity of the reaction = 1 + 1 = 2

Order of the reaction = 1 + 1 = 2

This is considered as an elementary reaction.

<u>Equation 4:</u> $NO_2(g)+CO(g)\rightarrow NO(g)+CO_2(g);Rate=k[NO_2]^2$

Molecularity of the reaction = 1 + 1 = 2

Order of the reaction = 2 + 0 = 2

In this equation, the order with respect to each reactant is not equal to its stoichiometric coefficient which is represented in the balanced chemical reaction. Hence, this is not considered as an elementary reaction.

Hence, the correct answer is $NO(g)+O_2(g)\rightarrow NO_2(g)+O(g);Rate=k[NO][O_2]$

3 0

3 years ago

The freezing point of a 0.30 m KCl solution will have the same freezing point that a 0.20 m Ca(NO3)2 solution.

igor_vitrenko [27]

False freezing point does not depend on volume

6 0

3 years ago

Read 2 more answers

In the Lewis structure for ICl2–, how many lone pairs of electrons are around the central iodine atom.

Stells [14]

Answer : The number of lone pairs of electrons around the central iodine atom are, 6 electrons

Explanation :

Lewis-dot structure : It shows the bonding between the atoms of a molecule and it also shows the unpaired electrons present in the molecule.

In the Lewis-dot structure the valance electrons are shown by 'dot'.

The representation of valence electrons of an atom by dots around the symbol of an element is said to be the Lewis-dot symbol.

In the representation of Lewis-symbol, one electron dot must put on each side of the element symbol then paired the electrons.

The given molecule is, $ICl_2^-$

As we know that iodine ans chlorine has '7' valence electrons.

Therefore, the total number of valence electrons in $ICl_2^-$ = 7 + 2(7) + 1 = 22

According to Lewis-dot structure, there are 4 number of bonding electrons and 18 number of non-bonding electrons.

Hence, the number of lone pairs of electrons around the central iodine atom are, 6 electrons

3 0

3 years ago