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3 years ago

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I NEED HELP FAST!!!!! Can you tell me about examples of physical and chemical compounds of matter??? I have a DBA in a few minut

es and I don't know!!! Please use easy to understand answers 'cause I'm a little under the weather.

1 answer:

o-na [289]3 years ago

7 0

Physical<span> properties </span>can<span> be observed or measured without changing the </span><span>composition of matter</span>

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Describe the overall structure or order of the scientific process.

shepuryov [24]

Answer:

Explanation:The scientific method is an empirical method of acquiring knowledge that has characterized the development of science since at least the 17th century. It involves careful observation, applying rigorous skepticism about what is observed, given that cognitive assumptions can distort how one interprets the observation. It involves formulating hypotheses, via induction, based on such observations; experimental and measurement-based testing of deductions drawn from the hypotheses; and refinement (or elimination) of the hypotheses based on the experimental findings. These are principles of the scientific method, as distinguished from a definitive series of steps applicable to all scientific enterprises.[1][2][3]

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3 years ago

In which chemical system is molecule to ion attractions present? A) KNO3(s) B) KNO3(l) C) KNO3(aq) D) KNO3(g)

Maurinko [17]

Answer:

$KNO_3 (aq)$

Explanation:

Potassium nitrate is a soluble salt which readily dissolves in a polar solvent, such as water. When solid potassium nitrate is dissolved in water, it dissociates into potassium cations and nitrate anions.

Due to the resultant ionic charges, the polar water molecules attract the resultant ions and potassium nitrate ions become hydrated, that is, surrounded by water molecules.

Nitrate, our anion, attracts the partially positive ends of water molecules by attracting them via hydrogen atom.

Potassium, the cation, attracts the partially negative end of water molecules by attracting via oxygen atom.

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3 years ago

What allowed Mendeleev to make predictions of undiscovered elements

Andrej [43]

Answer:

he predicted the properties from known elements above and belws the unknown in the same group

Explanation:

What allowed Mendeleev to make predictions of undiscovered elements

He realized that an element on this table with one known element above it and one known element below it had to have properties between the two known elements

How did Mendeleev predict gallium and germanium?

Based on gaps in the periodic table Mendeleev deduced that in these gaps belonged elements yet to be discovered. Based on other elements below and above in the same group he predicted the existence of eka-aluminum, eka-boron, and eka-silicon, later to be named gallium (Ga), scandium (Sc), and germanium (Ge).

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3 years ago

Read 2 more answers

Compound A has a partition coefficient (K) of 7 when comparing its solubility in CH2Cl2 to water ( K=11, [solubility of A in g/m

Hitman42 [59]

Answer:

The equation which will tell us how much of A that is mis inmthe water layer after partitioning is: 7 = (17 - x) g / 150 mL ÷ x g /100 mL

Explanation:

A partition coefficient is the ratio of the concentration of a substance in one solvent phase to the concentration in a second solvent phase when the two concentrations are at equilibrium. Usually the two phases are an organic phase and an aqueous phase. Thus, the partition coefficient K, of a compound is the ratio of the compound's concentration in the organic layer compared to the aqueous layer.

K = C₁/C₂ at equilibrium

In the compound A given, CH₂Cl₂ is the organic phase while water is the aqueous phase

Amount of A that is partitioned in between dichloromethane, CH₂Cl₂ and water, H₂O is 17.0 g

Let the amount of A that is dissolved in water be x g

Solubility of A in water given in g/mL = (x / 100) g/ml

Amount of A dissolved in dichloromethane, CH₂Cl₂ = (17 - x) g

Solubility of A in dichloromethane, CH₂Cl₂ given in g/mL = (17 - x/150) g/mL

Since the partition coefficient, K of compound A when comparing its solubility in CH₂Cl₂ to water is 7, that is;

K = [solubility of A in g/ml in CH₂Cl₂] / [solubility of A in g/ml in H2O] = 7

The equation for the amount of A in the water layer is given as follows:

7 = (17 - x) g / 150 mL ÷ x g /100 mL

Solving for x

7 = (17 -x) × 100 / 150x

7 × 150x = (17 - x) × 100

1050x = 1700 - 100x

1150x = 1700

x = 1700/1150

x = 1.48 g

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3 years ago

Who answers the three economic questions in a market economy? How is this different from command economy?

Natali [406]

Answer:

Market economies are characterized by their free markets. Examples are the United States and the United Kingdom.

That's pretty clear. What it means is that they trust in the free market and its operation to answer the questions of what to produce, how much to produce, and for whom.

Command economies are characterized by their control of markets. Examples are China and North Korea.

They rely on the government, <em>not the free market itself, </em>to control what should be produced. This makes for a more strict system that can pay off in the long run, but can also run the risk of being heavy-handed.

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