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3 years ago

Which of the following is an example of a chernical change?

Chemistry

2 answers:

matrenka [14]3 years ago

7 0

Answer:

the chemical change occur in burning paper.

boiling water does not make any chemical change

melting gold "

dissolving sugar in water "

in these examples the reactant remains as the same , even if you melt gold it is gold itself, it only change its state.

AVprozaik [17]3 years ago

6 0

Answer:

Burning paper.

Explanation:

A chemical change is a change that changes the molecular structure of the substance you are changes. Boiling water would make water vapour, which is still water thus it is a physical change. Dissolving sugar in water is still sugar in water thus it is a physical change. Melting gold makes liquid gold which is still gold thus it is a physical change. Burning paper however changes from paper to ash and smoke, which are different on the molecular level, therefore it is a chemical change.

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Draw the product formed when the compound shown below undergoes a reaction with hcl in ch2cl2.

Taya2010 [7]

The product formed when HCl and CH2Cl2 react is CH4
H
H-C- H methane structure
H

HCl react with CH2Cl2 to form methane (CH4) and chlorine gas(Cl2)
that is,

2HCl(g) + CH2Cl2(l) = CH4 (g) +2Cl2 (g)

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3 years ago

Does anyone know this!?

saul85 [17]

Answer:

I don’t know this answer sorry

Explanation:

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2 years ago

The following choices contain densities of various materials. Based on these data, which will yield the fastest seismic velocity

Eduardwww [97]

Answer:

D. 5.6 g/cm^3

Explanation:

On the average seismic velocity increases with increase in depth due higher the pressure and more compaction

sand and shales in the Niger Delta Basin density–velocity relationship is

P = 0.31×V^0.25

A derivation of the original Gardner equation to calculate the average densities for sands and shales in wells.

ρ = α ×V^β

where

ρ = bulk density in g/cm3,

V = P-wave velocity,

α = 0.31 for V (m/s) and 0.23 for V(ft/s) and

β = 0.25.

Such that

ρ = 0.31 ×V^0.25

So the fastest seismic velocity will be in the densest material which is D. 5.6 g/cm3

5 0

3 years ago

Formula of preparation of sodium hydroxide

Umnica [9.8K]

The chemical formula of sodium hydroxide is NaOH, and its molar mass is 40.01 g/mol. It is the alkali salt of sodium, and its structure is shown below:

It is an ionic compound consisting of sodium cation (Na+) and hydroxide (OH-) anion.

7 0

2 years ago

Which class of compounds contains only carbon, hydrogen, and nitrogen?

Likurg_2 [28]

<h2>Answer: </h2>

Nitrogen forms many thousands of organic compounds. Most of the known varieties may be regarded as derived from ammonia, hydrogen cyanide, cyanogen, and nitrous or nitric acid. The amines, amino acids, and amides, for example, are derived from or closely related to ammonia.

<h3>Explanation: </h3>

A carbohydrate has only Carbon, Hydrogen and Oxygen, with the hydrogen and oxygen in the ratio 2:1.

Examples are glucose C6H12O6 and table sugar C12H22O11

A protein is made of amino acids. Amino acids have an amino group which is −NH2.

So without nitrogen atoms the compound cannot be a protein.

Nucleic acids are organic compounds that contain carbon, hydrogen, nitrogen but they also contains phosphorus and oxygen. They are made of smaller units called nucleotides.

So;

Simple Amines are the class of organic compounds that only contains Carbon, Hydrogen and Nitrogen.

5 0

3 years ago

Read 2 more answers