What is the chemical equation for a reaction between copper (ll carbonate and heat?

What can be added to an atom to cause a nonvalence electron in the atom to temporarily become a valence electron?

vazorg [7]

Answer:

What can be added to an atom to cause a nonvalence electron in the atom to temporarily become a valence electron is energy.

Explanation:

The normal state of the atoms, where all the electrons are occupying the lowest possible energy level, is called ground state.

The valence electrons are the electrons that occupy the outermost shell, this is the electrons in the highest main energy level (principal quantum number) of the atom.

So, a nonvalence electron occupies an orbital with less energy than what a valence electron does; in consequence, in order to a nonvalence electron jump from its lower energy level to the higher energy level of a valence electron, the former has to absorb (gain) energy.

This new state is called excited state and is temporary: the electron promoted to the higher energy level will emit the excess energy, in the form of light (photons), to come back to the lower energy level and so the atom return to the ground state.

6 0

3 years ago

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Us

MrRissso [65]

Answer:

24.9%

Explanation:

According to this question, mole fraction of NaCl in an aqueous solution is 0.0927. This means that the mole percent of NaCl in the solution is:

0.0927 × 100 = 9.27%

Let's assume that the solution contains water (solvent) + NaCl (solute), hence, the mole fraction of water will be;

100% - 9.27% = 90.73%

THEREFORE, it can be said that, NaCl contains 0.0927moles while H2O contains 9.073moles

N.B: mole = mass/molar mass

Given the Molar Mass

NaCl: 58.44 g/mol

H2O: 18.016 g/mol

For NaCl;

0.0927 = mass/58.44

mass = 0.0927 × 58.44

5.42g

For H2O;

9.073 = mass/18.016

mass = 9.073 × 18.016

= 16.35g

Total mass of solution = 16.35g + 5.42g = 21.77g

Mass percent of NaCl = mass of NaCl/total mass × 100

% mass of NaCl = 5.42g/21.77g × 100

= 0.249 × 100

= 24.9%

5 0

3 years ago

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100 POINTS!!! WILL GIVE BRAINLIEST FOR DETAILED AND CORRECT ANSWER!!!

sveticcg [70]

Answer:

dissolve rocksalt in heated water

Explanation:

If the rock salt is one large chunk, grind it into a powder using a mortar and pestle or a coffee grinder.

Add 30-50 milliliters of water to six heaping spatula scoops of rock salt.

Stir to dissolve the salt.

Place the filter paper in the mouth of the funnel.

Place the evaporating dish under the funnel to collect the liquid.

Slowly pour the rock salt solution into the funnel. Make sure you don't over-fill the funnel. You don't want the liquid to flow around the top of the filter paper because then it isn't getting filtered.

Save the liquid (filtrate) that comes through the filter. Many of the mineral contaminants did not dissolve in the water and were left behind on the filter paper.

Place the evaporating dish containing the filtrate on the tripod.

Position the Bunsen burner under the tripod.

Slowly and carefully heat the evaporating dish. Be careful! If you apply too much heat, you might break the dish.

Gently heat the filtrate until all the water is gone. It's okay if the salt crystals hiss and move a little.

Turn off the burner and collect your salt. Although some impurities will remain in the materials, many of them will have been removed simply by using the difference in solubility in water, mechanical filtration, and by applying heat to drive off volatile compounds.

If you want to further purify the salt, you can dissolve your product in hot water and crystallize the sodium chloride from it.

6 0

3 years ago

How is it that when a salt sample dissolves in water, the delta S for the process is positive?

Bess [88]

Answer:-

Water is highly ordered. In water each oxygen atom is connected to others around it through hydrogen bonding via bridging hydrogen atoms. When a salt like NaCl is dissolved, some of these Hydrogen bonds break.

When a salt like NaCl dissolves in water, the NaCl breaks in to ions Na+ and Cl-.

The water molecules now surround these ions.

The slightly negative oxygen end of water molecule gets near the Na+, while the slightly positive Hydrogen of water molecule gets near the Cl-.

So before salt sample dissolve, the water molecules were highly ordered due to hydrogen bonding. Now after salt dissolve there is a decrease in order and thus an increase in disorder of the water molecules.

Due to increase in disorder, entropy which is a measure of disorder increases. Since entropy increases, delta S for the process is positive.

4 0

3 years ago

For an insoluble compound, how might you prevent formation of the precipitate

anastassius [24]

protect it by covering it by lyophilic sol.

8 0

3 years ago