a student reacted 40 drops of an unknown amine with 20 drops of iodomethane in 2 ml of a suitable solvent mixture. after 15 minutes of reaction, a white precipitate formed. the precipitate was isolated and its melting point was recorded to be 178 °c. what could this precipitate be?

Answer:

That would be ATP, hope this helps! :)

Explanation:

physical changes : boiling water, freezing water, a pencil being sharpened.

chemical change : rotting cheese, exploding dynamite.

Answer:

boiling water

a pencil being sharpened

freezing water

Explanation:

A change that does not lead to any difference in chemical composition of a substance is known as a physical change.

For example, shape, size, mass, volume, density, boiling point, etc of a substance are all physical properties.

On the other hand, changes that lead to bring change in chemical composition of a substance is known as a chemical change.

For example, exploding dynamite, rotting cheese etc are all chemical changes.

Chemical change is the change in which there is rearrangement of atoms and the new substances get formed.

Boiling water only changes the phase from liquid to gas and thus is a physical change.

Pencil on being sharpened only gets smaller in size and thus is a physical change.

exploding dynamite would result into formation of new substances and hence a chemical change.

Freezing water only changes the phase from liquid to solid and thus is a physical change.

Rotting cheese would result in formation of new substances and hence a chemical change.

Therefore, we can conclude that following are the physical changes in matter.

boiling water.

a pencil being sharpened.

freezing water.

Answer:

Their speed = 69.9043 miles per hour

Their speed = 112.5 kilometers per hour

Explanation:

Answer:  

Find moles of Known Substance (NaCl)

Moles of NaCl = mass ÷ molar mass

                        =  114.25 g ÷ 58.44 g/mol

                        = 1.955 mol

Use Mole Ratio of Known to Unknown (NaCl : NaClO₃) to Determine Moles of Unknown

The mole ratio of NaCl to NaClO₃ is 2 to 2 or simply 1 to 1.

This means that for each mole of NaCl produced the same number of moles of NaClO₃ was decomposed.

∴ since moles of NaCl = 1.955 mol,

then moles of NaClO₃ = 1.955 mol

Find Mass of Unknown

Mass of NaClO₃ = moles × molar mass

                           = 1.955 mol × 106.44 g/mol

                           =  208.09 g

Determine the Moles of Known (O₂)

moles of O₂ = (volume × density) ÷ molar mass

                    = (68.30 L × 0.0828 g/L) ÷ 32 g/mol

                    = 0.177 mol

Use Mole Ratio of Known to Unknown (O₂ : NaClO₃) to Determine Moles of Unknown

Mole ratio of O₂ : NaClO₃ is 3 : 2. Therefore for each mole of oxygen produced, ²/₃ the moles of NaClO₃ is produced.

∴ if moles of O₂  =  0.177 mol

then moles of NaClO₃ =  0.177 mol × ²/₃

                                     = 0.118 mol

Find the Number of Particles of Unknown

Number of particles  = moles × Avogadro's Number

                                  = 0.118 mol × (6.022 × 10²³ particles/mol)

                                  =  7.11 × 10²² particles

Answer:

Mass, volume, width, height, etc.

Explanation:

Extensive properties depend on the amount of material where intensive properties (color, luster, taste, odor, density, temperature, melting/boiling point) don't.

Answer:

$500

Explanation:

G00gle.

Answer:

argan can exist freely in nature because it has stable configuration whereas sodium atom cannot exist freely nature because do not have stable configuration.

Explanation:

brainiest!!!!!

Because that's the correct answer

Explanation:

land.

I think it is the answer

Answer:

land .......................

Answer:

Because combustion is a chemical change and not a physical change. Do, flammable and combustible gases burn and change into new substance.

As opposed to a physical change, combustion is a chemical transformation. Combustible and flammable gases do burn and transform into new substances.

Combustible materials are those that, when exposed to fire or heat, will ignite, burn, sustain combustion, or produce flammable gases in the form and circumstances anticipated for their application. Combustible materials include rubber, plastics, rubberized materials, and wood.

Depending on the environmental factors, most metals are flammable to varied degrees. With water, acids, and other chemicals, certain metals can react in ways that are hazardous. Some metals can spontaneously ignite and heat up.

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Answer:

maybe 25 joules

Explanation:

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If 5 J (joules) of electrical energy is used to power an iron, 25 joules of heat and steam should it be transformed into.

Energy is referred to by scientists as the capacity for work. People have figured out how to transform energy from one form to another and then use it to accomplish tasks, making modern civilization possible.

Walking and bicycling, driving cars on roads and boats through water, cooking meals on stoves, making ice in freezers, lighting our homes and workplaces, producing goods, and sending astronauts into space all require the usage of energy.

Energy is capable of changing its forms. For instance, a person's body stores chemical energy from the food they consume until they may use it as kinetic energy when working or playing.

Therefore, If 5 J (joules) of electrical energy is used to power an iron, 25 joules of heat and steam should it be transformed into.

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the fire spreading is what represents the form of heat transferring from one atom to another within an object and direct contact

Explanation:

Percent errors tells you how big your errors are when you measure something in an experiment. Smaller percent errors mean that you are close to the accepted or real value. For example, a 1% error means that you got very close to the accepted value, while 45% means that you were quite a long way off from the true value.

Answer:

b).   0.732

Explanation:

52g Na₂SO₄ x     1 mol Na₂SO₄       x      2 mol Na

                          -------------------------      --------------------  =  0.732 mol Na

                           142.04 g Na₂SO₄       1 mol Na₂SO₄

Atomic Mass Units

Na₂ = 22.99 x 2 = 45.98

S     = 32.06

O₄ = 16 x 4 = 64

Na₂SO₄ = 45.98 + 32.06 + 64 = 142.04

There are 2 moles of Na in 1 mole of Na₂SO₄

Answer:

Arsenic-tolerant GFAJ-1 bacteria were reported to have replaced some of the phosphorus (P) in their DNA with arsenic. ... These bacterial cells were very efficient at using the small amount of available phosphate in preference over the easily available arsenic. so yes.

Explanation:

hope this helps

Answer:

Yes

Explanation:

Hope everything goes well with your work :D

Answer:

7.06

Explanation:

because its improper

Answer:Pure water does not contain fluoride, but much drinking water does contain fluoride that is deliberately added to reduce tooth decay of children who drink the water. Some drinking water supplies also contain fluoride naturally.

Explanation:

in small doses not harmful

Fluoride is a chemical that is intentionally added to drinking water in order to prevent tooth decay in children. Pure water does not naturally contain fluoride. Some sources of drinking water naturally contain fluoride as well.

Fluoride is a chemical that is intentionally added to drinking water in order to prevent tooth decay in children. Pure water does not naturally contain fluoride. Some sources of drinking water naturally contain fluoride as well.

Compared to magnesium found in food, magnesium in water is present as hydrated ions, which are more easily absorbed. Thus, the role played by water magnesium in the prevention of magnesium insufficiency may be quite important for people who drink water with high magnesium levels.

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Answer:

The reaction type is double displacement

Answer:

Protons have a positive charge. Electrons have a negative charge. The charge on the proton and electron are exactly the same size but opposite. Since opposite charges attract, protons and electrons attract each other.

Explanation:

Answer:

false

Explanation:

hope this helps you

Answer:

False, if the flask becomes colder it's endothermic. I hope this helps! :)

Answer:

batqyqy6w

Explanation:

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Answer:

The produced mass of copper should equal the starting mass of copper.

Answer:

Atomic mass of Sodium is 22.9897 u. Note that, each element may contain more isotopes, therefore this resulting atomic mass is calculated from naturally-occuring isotopes and their abundance. The unit of measure for mass is the atomic mass unit (amu). One atomic mass unit is equal to 1.66 x 10 -24 grams.

Explanation:

Answer:

its a substance

Explanation: