Summarize the process a scientist goes through to come up with a<br> satisfactory solution.

MrRa [10]

3. in every chemical or physical change

6 0

3 years ago

Placing a suspect at the scene of a crime is an important element in criminal investigation. This can be achieved through the lo

r-ruslan [8.4K]

Answer:A) cotton

A fiber if available in trace or appropriate amount can link a suspect to a crime.Solubility is a preliminary test performed for identification of the type of fiber. In this method small amount of fiber evidence is dissolved in the suitable solvent to identify it's type. Some fibers completely get solublize in the solvent, some get partially soluble and other can only change their color or do not dissolve at all.

According to the given situation, the fiber dissolved in hydrochloric acid can be cotton. As the fibers of cotton are soft and slender and will get easily solubilize in hydrochloric acid.

3 0

4 years ago

How can a substance stay at a certain temperature even though it is being heated?

SOVA2 [1]

The temperature of a certain substance can be seen as the average speed of the atoms or molecules in that substance. In the liquid state of a substance the forces between the atoms or molecules are strong enough to keep them together, however with enough freedom to move, unlike in the solid state. If we would have a closer look at the surface of a liquid from sideways, we would see water molecules jumping out of the water and reentering it again. The lower the water temperature would be the lesser the amount of water molecules leaving the liquid phase would be. If water would be heated up and the temperature will reach 100 degrees C at normal atmospheric pressure, more water molecules would leave the water than reentering. Boiling has started. The temperature of the water remains at 100 degrees C, if the heating continues as the average speed of molecules will not increase, only the rate of molecules leaving the water will increase, until all the water in liquid state has been vapourized. The amount of heat needed to vapourize liquid water is called latent heat. Latent heat is a very important driving factor in the atmosphere and thus the weather.

5 0

3 years ago

How many atoms are in 22 grams of copper metal?

strojnjashka [21]

Atomic mass Cu = 63.546 a.m.u

63.546 g ---------------- 6.02x10²³ atoms
22 g --------------------- ??

22 x (6.02x10²³ ) / 63.546 => 2.08x10²³ atoms

hope this helps!

6 0

3 years ago

How many grams of copper (II) hydroxide can be prepared from 2.4 grams of copper (II) nitrate (Cu(NO3)2 ) and excess sodium hydr

andreyandreev [35.5K]

Answer:

percentage yield = 67%

Explanation:

Mass of Cu(NO₃)₂ = 15.25 g

Mass of NaOH = 12.75 g

Percentage yield = ?

Solution:

Cu(NO₃)₂ + 2NaOH → Cu(OH)₂ + 2NaNO₃

Moles of Cu(NO₃)₂:

Number of moles = mass/ molar mass

Number of moles = 15.25 g /187.56 g/mol

Number of moles = 0.08 mol

Moles of NaOH :

Number of moles = mass/ molar mass

Number of moles = 12.75 g / 40 g/mol

Number of moles = 0.32 mol

Now we will compare the moles of Cu(OH)₂ with NaOH and Cu(NO₃)₂. NaOH : Cu(OH)₂

2 : 1

0.32 : 1/2×0.32 = 0.16 mol

Cu(NO₃)₂ : Cu(OH)₂

1 : 1

0.08 : 0.08

The number of moles produced by Cu(NO₃)₂ are less so it will limiting reactant.

Mass of Cu(OH)₂:

Mass = number of moles × molar mass

Mass = 0.08 mol × 97.6 g/mol

Mass = 7.808 g

Theoretical yield = 7.808 g

Percent yield:

percentage yield = Actual yield/ theoretical yield × 100

percentage yield = 5.23 g/ 7.808 g × 100

percentage yield = 0.67 × 100

percentage yield = 67%

5 0

3 years ago

Summarize the process a scientist goes through to come up with a satisfactory solution.