A homogeneous substance that can be seperated into two or more substances only by a chemical change is an ?

Final answer:

To calculate the proper dosage of cough medicine for a 2-year-old child, you need to know their weight. The dosage is 5.0 mg/kg, so you can calculate the dosage by multiplying the weight of the child in kilograms by 5.0 mg. The cough syrup is supplied in a liquid that contains 50.0 mg/mL, so you need to convert the dosage into milliliters.

Explanation:

To calculate the proper dosage of cough medicine for the 2-year-old child, you need to know the weight of the child. Let's assume the child weighs 10 kilograms. The dosage is 5.0 mg/kg, so for a 10-kilogram child, the proper dosage would be 50.0 mg per dose. However, the cough syrup is supplied in a liquid that contains 50.0 mg/mL, so you need to convert the dosage into milliliters.

Since the syrup has a concentration of 50.0 mg/mL, you would need 1 milliliter of syrup to achieve a dosage of 50.0 mg. Therefore, the proper dosage of cough medicine for the 2-year-old child would be 1 milliliter of syrup per dose, three times a day.

Answer:

Table Sugar

Explanation:

The unknown substance must be table sugar.. At 200 °C, the only substances that would have melted would be water and table sugar. Everything else has a higher melting point, thus they would still be solid.

The answer is A (27)

3.8 km/sec is equivalent to approximately 74,649,628.96 miles/year.

3.8 km/sec will be converted to miles/year using the formulas below: Convert km/sec to km/hour in step one.We must multiply km/sec by 3600 (the number of seconds in an hour) in order to translate km/sec to km/hour.3.8 km/sec divided by 3600 equals 13680 km/h.

Step 2: Convert from km/h to mi/h.

We must divide km/hour by 1.609344 (the number of kilometres in a mile) to convert km/hour to miles/hour.8508.856 miles per hour (13680 km/h x 1.609344)3. Convert miles per hour to miles per year.

We must multiply miles/hour by 8760 (the number of hours in a year) in order to convert miles/hour to miles/year.8760 divided by 8508.856 equals 74649628.96 miles per year.3.8 km/sec is therefore comparable to roughly 74,649,628.96 miles per year.

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This atom is very likely to bond with another atom.

k12 student, hope i helped! good luck

Final answer:

When water is heated, its volume increases. For every 1°C increase in temperature, the volume of water increases by about 0.00021 liters. Therefore, when a liter of water is heated from 20°C to 50°C, its volume will increase by approximately 6.3 milliliters.

Explanation:

When water is heated, it expands and its volume increases. This is because the molecules in the water gain energy and start moving faster, causing the spaces between them to increase.

In this case, when a liter of water is heated from 20°C to 50°C, its volume will increase. The exact amount of increase in volume can be calculated using the coefficient of thermal expansion of water, which is approximately 0.00021 per degree Celsius.

This means that for every 1°C increase in temperature, the volume of water will increase by about 0.00021 liters. So, for a 30°C increase in temperature (from 20°C to 50°C), the volume of water will increase by 0.00021 * 30 = 0.0063 liters, or approximately 6.3 milliliters.

Chemical and physical changes are characterized by the formation and conversion of the state of matter. The burning of gasoline is chemical and its evaporation is a physical change.

Physical change has been defined as the alteration of the physical properties of substances that might include volume, size, shape, density, mass, etc. They are reversible and can be converted back to their original state. The evaporation of gasoline involves the conversion of liquid into gas.

On the other hand, chemical change involves the combination, substitution, and deletion of the atoms of the compound to form an irreversible product. The new product formed has different properties. The burning of gasoline produces carbon dioxide and water.

Therefore, the burning of gasoline is a chemical change, whereas evaporation is a physical change.

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Answer:

Density of Solid A is greater than B

Explanation:

Given:

Mass of Solid A = 2 g

Mass of solid B = 0.5 g

Volume of both solids = 6 cm3

To determine:

Densities of A and B

Calculation:

Density of a substance is the mass occupied by it in unit volume

[tex]Density = \frac{Mass}{Volume}[/tex]

For Solid A:

[tex]Density = \frac{2\ g}{6\ cm3} =0.33\ g/cm3[/tex]

For Solid B :

[tex]Density = \frac{0.5\ g}{6\ cm3} =0.083\ g/cm3[/tex]

Therefore solid A is more dense than solid B

Answer: The mass of magnesium chloride produced in the given reaction is 16.09 grams.

Explanation:

We are given:

Moles of magnesium = 3.38 mol

Moles of hydrochloric acid = 3.38 mol

The chemical equation for the reaction of magnesium and hydrochloric acid follows:

[tex]Mg+2HCl\rightarrow MgCl_2+H_2[/tex]

By Stoichiometry of the reaction:

2 moles of hydrochloric acid reacts with 1 mole of magnesium.

So, 3.38 moles of hydrochloric acid will react with = [tex]\frac{1}{2}\times 3.38=1.69mol[/tex] of magnesium.

As, given amount of magnesium is more than the required amount. So, it is considered as an excess reagent.

Thus, hydrochloric acid is considered as a limiting reagent because it limits the formation of product.

By Stoichiometry of the reaction:

2 moles of hydrochloric acid is producing 1 mole of magnesium chloride.

So, 3.38 moles of hydrochloric acid will react with = [tex]\frac{1}{2}\times 3.38=0.169moles[/tex] of magnesium chloride.

Now, calculating the mass of magnesium chloride by using equation:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]

Molar mass of magnesium chloride = 95.21 g/mol

Moles of magnesium chloride = 0.169 moles

Putting values in above equation, we get:

[tex]0.169mol=\frac{\text{Mass of magnesium chloride}}{95.21g/mol}\\\\\text{Mass of magnesium chloride}=16.09g[/tex]

Hence, the mass of magnesium chloride produced in the given reaction is 16.09 grams.

Answer: Option (c) is the correct answer.

Explanation:

A fat is defined as a substance which is highly soluble in organic solvents but it is largely insoluble in water.

These molecules are less soluble in water because it contains three non-polar fatty acids and no polar or charged head like a phospholipid has.

On the other hand, a phospholipid molecule contains a hydrophilic head that is highly soluble in water.

Hence, due to the presence of hydrophilic group a phospholipid is soluble in water.

Thus, we can conclude that a fat molecule is less soluble in water because it has three non-polar fatty acids and no polar or charged head like a phospholipid has.

When light is emitted, atoms in a neon light loose energy  according to the concept of emission spectrum.

Emission spectrum is defined as a spectrum of a chemical compound or substance composed of frequencies of electromagnetic radiation. Radiations which are emitted while electron make transition from higher to lower energy level.

Energy of photon is equal to the difference between the two energy states . There are many possible electronic transitions in an atom and every transition has a specific wavelength.

Collection of different transitions with respect to different wavelengths makes up an emission spectrum.Emission spectrum of each element is unique and therefore spectroscopy is used to identify elements which are present in different substances.

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Answer:

compond

Explanation:

Atomic number represents the number of protons, while atomic mass represents the weighted average of the masses of an element's naturally occurring isotopes.

Answer: [tex]3CaCO_3(aq)+2Li_3N(aq)\rightarrow Ca_3N_2+3Li_2CO_3[/tex]

Explanation: According to the law of conservation of mass, mass can neither be created nor be destroyed.

The mass of products must be same as that of the mass of reactants. For this the number of atoms of each element must be same on both sides of the arrow. Thus we need to balance the chemical equations.

[tex]3CaCO_3(aq)+2Li_3N(aq)\rightarrow Ca_3N_2+3Li_2CO_3[/tex]

A substance that decreases hydrogen ion concentration and increases pH when dissolved in water is known as a base, which can provide hydroxide ions to combine with hydrogen ions, increasing the pH.

A substance that decreases H+ concentration and increases pH when it dissociates in water is called a base. Bases can be substances that provide hydroxide ions (OH-) or other negatively charged ions that readily combine with hydrogen ions, which leads to a decrease in the aqueous hydronium concentration and as a result, increases the pH of the solution. This process often involves hydroxide ions binding to free hydrogen ions, forming new water molecules, and thereby raising the pH.

Mathematically, pH is expressed as pH = -log10 [H+], where a high concentration of hydrogen ions yields a low pH number, and conversely, a low concentration of hydrogen ions results in a high pH. The concept of pH is central to understanding acid-base chemistry and the behavior of substances in solution.

Answer:

The given blank can be filled with carbon dioxide.

Explanation:

Carbon dioxide one of the by-products of fermentation is used in the production of carbonated beverages and in manufacturing of bread. In the brewing industry, alcoholic fermentation takes place in which transformation of sugar is done into ethyl alcohol and carbon dioxide. The carbon dioxide, which is the by-product in the process bubbles through the liquid and disperses into the air. The same phenomenon of carbon dioxide is used to cause rising of the bread.

A scientific law is a concise statement describing how the things act in natural world. The scientific laws are universal and and not falsifiable up to greater extend. Hence, option 4 is correct.

Scientific laws are scientific statements that describes a natural phenomenon or how nature works under a set of conditions. Unlike theories scientific laws are very concise and clear cut statement without more explanations.

Scientific laws are universal and must be in a harmony in between other laws. They can be proved by scientific experiments but cannot be falsifiable up to an extend.

A scientific law can be represented by a simple mathematical expression or a sentence. They clearly states how things act on the natural world. They are should be forwarded by observable evidence and scientific experiments. Hence, option 4 is correct.

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A mathematical equation is typically an example of a scientific law, representing a concise description of a relationship in nature supported by scientific evidence and experiments. It can also serve as a model, but it is not usually an example of a scientific theory. So the correct option is the second option.

A mathematical equation in the context of science is often a way of expressing a scientific law. This is because scientific laws are frequently described using mathematical formulas that stipulate a consistent relationship between variables, which is expected to hold true universally. For example, Newton's second law of motion which is framed as F = ma where F stands for force, m for mass, and a for acceleration, succinctly describes the relationship between these three quantities. Unlike scientific theories, which are more complex and typically cannot be condensed into a single equation, a law is more concise and is often supported by repeated experiments and observations.

Therefore, a mathematical equation is an example of a scientific law. It is a model of sorts, as it can be used to predict and understand real-world phenomena based on the relationships it describes. Importantly, while theories provide a broader and more detailed explanation of natural phenomena and are the end result of the scientific method, laws describe more specific actions or relationships.

In summary, while a mathematical equation can be part of scientific laws and models, it is not typically an example of a scientific theory.

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