help please
Assuming that the trends continue, which of the following compounds do you predict will have the GREATEST solubility at 120°C?

A.
Ce2(SO4)3

B.
K2Cr2O7

C.
Pb(NO3)2

D.
NaCl

Answer:

A pure substance is a substance or an element whose impurities are extracted by concentration by chemical means.

e.g Aluminium is made pure by concentration of it's ore, bauxite by treatment with excess Sodium Hydroxide solution.

Answer: The percent by mass concentration is 33.3 %

Explanation:

Mass percent is the ratio of mass of solute to the mass of solution in terms of percentage.

mass of solute = 50 g

mass of solution = [tex]{\text {density of solution}}\times {\text {volume of solution}}=1.5g/ml\times 1000ml=1500g[/tex]

Mass percentage = [tex]\frac{50g}{1500g}\times 100\%=33.3\%[/tex]

Thus percent by mass concentration of 1000 ml of a solution (d=1.5 g/ml) that contains 50 g of solute in it is 33.3 %

Answer:

I think hydrogen because Hydrogen combined with one atom with oxygen and in hydrogen peroxide. It has two atoms of hydrogen and 2 atoms of oxygen. Therfore it should be a compound.

Answer:

alcohol

Explanation:

Answer:

Bonds are polar when one element in a compound is more electronegative than the other. This creates a dipole in the molecule where one end of the molecule is partially positive and one end is partially negative

Explanation:

Answer:

pH = 6.999

The solution is acidic.

Explanation:

HBr is a strong acid, a very strong one.

In water, this acid is totally dissociated.

HBr + H₂O  →  H₃O⁺  +  Br⁻

We can think pH, as - log 7.75×10⁻¹² but this is 11.1

acid pH can't never be higher than 7.

We apply the charge balance:

[H⁺] = [Br⁻] + [OH⁻]

All the protons come from the bromide and the OH⁻ that come from water.

We can also think [OH⁻] = Kw / [H⁺] so:

[H⁺] = [Br⁻] + Kw / [H⁺]

Now, our unknown is [H⁺]

[H⁺] =  7.75×10⁻¹² + 1×10⁻¹⁴ / [H⁺]

[H⁺] = (7.75×10⁻¹² [H⁺] + 1×10⁻¹⁴) /  [H⁺]

This is quadratic equation:  [H⁺]² - 7.75×10⁻¹² [H⁺] - 1×10⁻¹⁴

a = 1 ; b = - 7.75×10⁻¹² ; c = -1×10⁻¹⁴

(-b +- √(b² - 4ac) / (2a)

[H⁺] = 1.000038751×10⁻⁷

- log [H⁺] = pH → 6.999

A very strong acid as HBr, in this case, it is so diluted that its pH is almost neutral.

In the case when the HCI should be added so it should be shifted to reactants.

It is the solution that should be considered as the aqueous solution that comprise of the mixture of the weak acid and the conjugate base.

Here the ph level should be change very less at the time when the small amount of the strong acid should be added.

Therefore, it  should be shifted to reactants.

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Answer:

Na2SO4

Explanation:

Na2SO4 dissociates completely in solution to yield ions therefore it is the strongest electrolyte.

The question is incomplete as the table is missing but I will try to explain as generally as possible. Recall that an electrolyte is a compound that conducts electricity in solution.

Also recall that the number of ions available in solution determines the electrolytic strength of a substance. Hence, Na2SO4 dissociates completely in solution to yield ions therefore it is the strongest electrolyte.

Learn more about electrolytes: https://brainly.com/question/1301963

Answer:

False

Explanation:

False : It is better they are closer together

The RF ( retention factor  ) is calculated with this formula

= distance travelled / distance travelled by solvent

And the larger the RF factor of a compound the less polar the compound ( i.e. it will not stick to the stationary phase ) hence it is better the RF values of the components to be closer

Answer:

True

Explanation:

The resulting Rf factor, which has no units, is dependent upon the specific stationary and mobile phase used. Chromatogram results are considered to have better resolution if the Rf values of the components being separated are farther apart (e.g. 0.3 and 0.7) rather than closer together (e.g. 0.4 and 0.5). The distance the compound moves relative to the distance the solvent (or mobile phase or eluent) moves is a characteristic of that compound. (where Rf is equal to distance compound moved divided by solvent front distance)

Answer:

11

Explanation:

Sodium is a chemical element with the symbol Na and atomic number 11.

Answer:

22.99g/mol (in this case 23g/mol)

Answer:

weathering and erosion

Explanation:

Sand forms when rocks break down from weathering and eroding over thousands and even millions of years. Rocks take time to decompose, especially quartz (silica) and feldspar. Often starting thousands of miles from the ocean, rocks slowly travel down rivers and streams, constantly breaking down along the way.

Answer:

weathering and erosion

Answer:

The dating of rocks is important because:

Explanation:

its important  to know how the rocks have changed.

Answer:

[tex]100 \times 13.5 = ikw n bahaa[/tex]

IKAW na mag tayms

Answer:

Of course the answer is gold

Explanation:

Gold is used for making jewellery and not aluminium,iron or copper

Answer:

copper or gold.

Explanation:

Copper is also a good material for accessories. Even in the ancient times, those who can’t afford gold jewelry wear copper jewelry instead. It offers design flexibility too due to its high ductility.

Answer:

methylpentanoic acid,,,,,I guess so

The following carboxylic acid is 2-methylpentanoic acid.

A carboxylic acid is an organic compound that contains the carboxyl functional group. The general formula for a carboxylic acid can be abbreviated as R−COOH.

Pentanoic acid can be prepared by reacting a butyl halide with magnesium to obtain a Grignard reagent, which is further reacted with carbon dioxide to give valeric salt.

Hence, the following carboxylic acid is 2-methylpentanoic acid.

Learn more about the carboxylic acid here:

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Answer:

Hydroelectric pumped storage can be used to eliminate the conditional nature of wind and solar energy. At times of peak production of energy from either solar or wind (during summer and windy days), the excess electrical energy produced can be stored using hydroelectric pumped storage methods. When conditions no longer favour energy production from either wind or solar sources, these stored energy can then be regenerated for use.

Explanation:

Pumped-storage hydroelectricity is a type of hydroelectric energy storage used by electric power systems to store excess electrical power during periods of low demand for later release at periods when demand for energy rises again. It stores energy in the form of gravitational potential energy of water, pumped from a lower level reservoir to a higher level reservoir.

At times of low electrical demand, excess generated energy is used to pump water into the upper reservoir. When there is higher demand, water is released back into the lower reservoir through a turbine, generating electricity.

This form of energy storage is useful in circumventing the conditional nature of renewable energy sources such as wind and solar energy. At times of peak production of energy from either solar or wind (during summer and windy days), the excess electrical energy produced can be stored using hydroelectric pumped storage methods. When conditions no longer favour energy production from either wind or solar sources, these stored energy can then be regenerated for use.

Answer:

what is the gas that is produced.

Answer:

the oxidizing agent undergoes oxidation and

the reducing agent undergoes reduction simultaneously

Answer:Switch off lighting in refrigeration areas when not in use?

Explanation:

Answer:

ph=5.2 solution is acidic

Answer:

0.96 J/g °C

General Formulas and Concepts:

Thermochemistry

Specific Heat Formula: q = mcΔT

Explanation:

Step 1: Define

[Given] m = 5.0 g

[Given] ΔT = 22.0 °C - 20.0 °C = 2.0 °C

[Given] q = 9.6 J

[Solve] c

Step 2: Solve for c

Answer:

(1) Nuclear reactions entail a transition in the nucleus of an atom, which normally results in the formation of a new substance. Chemical reactions, on the other hand, only involve electron rearrangement and do not involve nuclei modifications. (4) Nuclear reactions are unaffected by the element's chemical form.

Explanation:

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Answer:

a atoms

Explanation:

Answer:

C. 8.55 atoms

Explanation:

Answer:

Answered below

Explanation:

>> ice is solid

>> water is liquid

>> Steam is gas

>> Ice → water = melting

>> water → steam = evaporation

>> steam → water = condensation

>> water → ice = freezing

Answer:

C

Explanation:

Answer:

D)

Explanation:

On land, volcanoes form when one tectonic plate moves under another. Usually a thin, heavy oceanic plate subducts, or moves under, a thicker continental plate. When this happens, the ocean plate sinks into the mantle.

Answer: pls mark brainliest

Explanation: i think so its D