Describe three signs that a chemical reaction has taken place and give an example of each sign

Recall that you're hypothesis is that these values are the fractions of atoms that are still radioactive after n half life cycle

Sergeu [11.5K]

A= 0.5, B = 0.25 , C = 0.125, D = 0.015625 and E = 0.00390625

<h3>What is a hypothesis?</h3>

A research hypothesis is a statement of expectation or prediction that will be tested by research. Before formulating your research hypothesis, read about the topic of interest to you.

Half life of a substance is defined as the amount of time taken by the substance to reduce to half of its original amount.

Here n represents the number of half lives.

The amount of substance that remains after n half lives can be calculated using the given formula,

So when we have n =1,

Fraction of substance that remains = 0.5¹ = 0.5.

That means after first half life over, the amount of substance that remains is 0.5 times that of original.

Therefore we have A = 0.5

When n = 2, we have 0.5² = 0.25

So when 2 half lives are over, the amount of substance that remains is 0.25 times that of original

Therefore B = 0.25

When n = 3, we have 0.5³ = 0.125

So when 3 half lives are over, the amount of substance that remains is 0.125 times that of original.

Therefore we have C = 0.125

When n = 6 , we have 0.5⁶ = 0.015625

So D = 0.015625

When n = 8, we have 0.5⁸ = 0.00390625

Therefore E = 0.00390625

The values for A, B, C, D and E are 0.5, 0.25, 0.125, 0.015625 and 0.00390625 respectively.

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4 0

2 years ago

Consider a disubstituted aromatic compound. The parent name is benzene and there is a chloro and bromo substituent. Disubstitute

Marina86 [1]

Answer:The correct names for the structure are:

--> 1. 1-bromo-3-chlorobenzene.

--> 3. meta-bromochlorobenzene.

--> 6. m-bromochlorobenzene.

Explanation:

Benzene is the simplest member of the aromatic hydrocarbons. It has a ring structure consisting of six carbon and six hydrogen atoms. This equally means that a benzene can have up to six substituents. One of the chemical properties is that benzene and other members of its series undergo substitution reaction whereby one or more of its six hydrogen atoms is replaced by monoatomic reagents.

Disubstituted benzene consists of two substituents which are described based on either numerical locants or specific words for the three possible forms.

The numerical locant method are used the same naming substitutes of other hydrocarbons. From the question, the numerical locant method was derived through using the following steps:

--> the functional group is benzene

--> there are two substituents which includes bromine( written as bromo) and chlorine ( written as chloro)

--> while placing the number, it's done alphabetically ('1-bromo' comes before '3-chloro') in a clockwise manner. This is to give chorine the lowest locant number.

The second naming method for a disubstituted benzene is the the ortho-, meta-, para- (or their singel letter equivalent) nomenclature method. This is only used for benzene structures.

--> ortho or O : this is used when the substituents are close to each other in the benzene ring.

--> meta or (m) : This is used when the substituents are separated by one carbon in the benzene ring.

--> para or (p): This is used when the substituents are across each other in the benzene ring

From the question, the bromine substituent is separated from the chlorine by one carbon atom, therefore it's meta-bromochlorobenzene or m-bromochlorobenzene.

8 0

3 years ago

Please Help Me!

S_A_V [24]

Answer:

The answer to your question is SO₂ + 3H₂ ⇒ H₂S + 2H₂O

Explanation:

Reaction

SO₂ + H₂ ⇒ H₂S + H₂O

Reactants Elements Products

1 Sulfur 1

2 Hydrogen 4

2 Oxygen 1

This reaction is unbalanced so we need to balance it.

SO₂ + 3H₂ ⇒ H₂S + 2H₂O

Reactants Elements Products

1 Sulfur 1

6 Hydrogen 6

2 Oxygen 2

Now, the reaction is balanced

3 0

3 years ago

Vitamin D has a percent composition of 42.98% C, and 57.02% H. Its molecular

Alex73 [517]

Answer:

Dont use alot of points

Explanation:

people scam like me and ay the wrong answer and get the points :|

3 0

3 years ago

Suppose 110.0 mL110.0 mL of hydrogen gas at STP combines with a stoichiometric amount of fluorine gas and the resulting hydrogen

Fittoniya [83]

Suppose 110.0 mL of hydrogen gas at STP combines with a stoichiometric amount of fluorine gas and the resulting hydrogen fluoride dissolves in water to form 150.0 mL of an aqueous solution. 0.032 M is the concentration of the resulting hydrofluoric acid.

<h3>What is Balanced Chemical Equation ?</h3>

The balanced chemical equation is the equation in which the number of atoms on the reactant side is equal to the number of atoms on the product side in an equation.

Now write the balanced chemical equation

H₂ + F₂ → 2HF

<h3>What is Ideal Gas ?</h3>

An ideal gas is a gas that obey gas laws at all temperature and pressure conditions. It have velocity and mass but do not have volume. Ideal gas is also called perfect gas. Ideal gas is a hypothetical gas.

It is expressed as:

PV = nRT

where,

P = Pressure

V = Volume

n = number of moles

R = Ideal gas constant

T = temperature

Here,

P = 1 atm [At STP]

V = 110 ml = 0.11 L

T = 273 K [At STP]

R = 0.0821 [Ideal gas constant]

Now put the values in above expression

PV = nRT

1 atm × 0.11 L = n × 0.0821 L.atm/ K. mol × 273 K

$n = \frac{1\ \text{atm} \times 0.11\ L}{0.0821\ \text{L. atm/ K. mol} \times 273\ K}$

n = 0.0049 mol

<h3>How to find the concentration of resulting solution ? </h3>

To calculate the concentration of resulting solution use the expression

$C = \frac{n}{V}$

$= \frac{0.0049}{0.15}$

= 0.032 M

Thus from the above conclusion we can say that Suppose 110.0 mL of hydrogen gas at STP combines with a stoichiometric amount of fluorine gas and the resulting hydrogen fluoride dissolves in water to form 150.0 mL of an aqueous solution. 0.032 M is the concentration of the resulting hydrofluoric acid.

Learn more about the Ideal Gas here: brainly.com/question/25290815
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4 0

2 years ago