What is the weight of 4.30 mole of sodium

Q = mct  

-Q= energy in Joules  

-m = mass in grams  

-c= specific heat capacity in J/g degree C  

-t = delta temperature in degrees Celsius  

So,  

Q = m c t  

Q = (7 grams)(0.448J/g C)(750 C - 25 C)  

Q = 2273.6 J  

Your final answer = 2273.6 Joules

Energy is the amount required by the substance to proceed with the chemical reactions. The energy required by the iron nail will be 2273.6 joules.

Energy is the product of the mass, specific heat capacity and change in the temperature. It is given as:

[tex]\rm Q = mC\Delta T[/tex]

Given,

Mass of the iron nail (m)= 25.5 gm

Specific heat capacity of iron (C) = 0.4494 J/g per degree C

Change in temperature = 725 degrees Celsius

Substituting values in the equation:

[tex]\begin{aligned} \rm Q &= \rm mC\Delta T\\\\&= 7\times 0.448\times 725\\\\&= 2273.6\;\rm J\end{aligned}[/tex]

Therefore, 2273.6 joules is energy.

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NaCl(s)=NaCl(aq) is a physical change as it represents a state change from solid to aqueous but retains the same chemical nature, Sodium Chloride (NaCl). The other choices show chemical changes.

The correct option is c.

The question is asking which of the choices represents a physical change. A physical change involves changes in the state of a substance but not its chemical nature. The best answer here is option C: NaCl(s)=NaCl(aq). In this reaction, solid sodium chloride (NaCl) is dissolving in water to form an aqueous solution, which is just a change in the state from solid to aqueous but the chemical nature (NaCl) remains the same. This is a clear demonstration of a physical change whereas options A, B, and D show chemical changes where new substances are formed.

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C. [tex]NaCl(s) \rightarrow NaCl(aq)[/tex]  shows a physical change.

A physical change is a type of change in which the form of matter is altered, but one substance is not transformed into another. Examples of physical changes include changes in state such as melting, freezing, and dissolving.

A. [tex]H_2(g) + O_2(g) \rightarrow H_2O(l)[/tex]
This is a chemical change because new substances with different chemical properties are formed: hydrogen and oxygen combine to form water.

B. [tex]2CH_3OH(l) + 3O_2(g) \rightarrow 2CO_2(g) + 4H_2O(l)[/tex]
This is another chemical change, involving the combustion of methanol to form carbon dioxide and water.

C. [tex]NaCl(s) \rightarrow NaCl(aq)[/tex]
This is a physical change. When sodium chloride (table salt) dissolves in water, it dissociates into ions but does not undergo any chemical change.

D. [tex]2AgNO_3(aq) + CaBr_2(aq) \rightarrow 2AgBr(s) + Ca(NO_3)_2(aq)[/tex]
This is a chemical change, where silver nitrate and calcium bromide react to form silver bromide and calcium nitrate, both of which are new substances.

like what are they made of? if so iron, due to iron oxide appearing as red hence why mars is red

Final answer:

The triple point on a phase diagram represents the only combination of temperature and pressure at which all three phases can exist simultaneously and are in equilibrium.

Explanation:

The triple point on a phase diagram refers to the point where the solid/liquid, liquid/gas, and solid/gas lines intersect. It represents the only combination of temperature and pressure at which all three phases can exist simultaneously and are in equilibrium. An example is the triple point of water, which occurs at 273.16 K (0.01°C). At this point, water can exist simultaneously as solid ice, liquid water, and water vapor.

The formation of bubbles and the change in color of the food item are signs of a chemical reaction, indicating the production of gas and the creation of new substances.

When a food item left out of the refrigerator turns brown, forms bubbles, and releases gas, the signs that a chemical reaction has occurred include the production of gas (evidenced by bubbles) and a change in color. These are key indicators that the original substances have undergone a chemical change to form new substances with different properties. While heat can be absorbed or produced during a chemical reaction, the question does not specify that this occurred, and there is no mention of a precipitate being formed.

Answer: by lowering the activation energy.

Explanation:

Activation energy is the extra energy that must be supplied to reactants in order to cross the energy barrier and thus convert to products.

A catalyst is a substance which increases the rate of a reaction by taking the reaction through a different path which involves lower activation energy and thus more molecules can cross the energy barrier and convert to products.

The catalyst itself does not take part in the chemical reaction and is regenerated as such at the end.

The correct answer is C. A positive calcium ion and a negative oxygen ion

Explanation:

In chemistry, an ionic bond occurs as ions with opposite charges attract each other and then create a bond due to the transference of electrons from one atom to other. This means, this type of bond occurs between an atom that is positively charged and one that is negatively charged, therefore, the two particles that can form an ionic bond are "A positive calcium ion and a negative oxygen ion" because these two have opposite charges (one is positively charged and one is negatively charged) and therefore electrons can be transferred from one atom to another forming an ionic bond.

Answer: [tex]5.2\times 10^{22} atoms[/tex] of iodine are present in 12.75 grams of [tex]CaI_2[/tex].

Explanation:

[tex]moles=\frac{\text{given mass of the compound}}{\text{molar mass of the compound}}[/tex]

Moles of Calcium iodide :

Moles of [tex]CaI_2=\frac{12.75 g}{293.8 g/mol}=0.0433 moles[/tex]

number of molecules of [tex]CaI_2[/tex] in 0.0433 moles = [tex]N_A\times \text{number of moles}=6.022\times 10^{23}\times 0.0433=2.60\times 10^{22} molecules [/tex]

In one molecule of calcium iodide there are two iodine atoms, then number of iodine atoms in [tex]2.60\times 10^{22} molecules [/tex] of [tex]CaI_2[/tex]

[tex]2\times 2.60\times 10^{22} atoms=5.2\times 10^{22} atoms[/tex]

Hence, there are [tex]5.2\times 10^{22} atoms[/tex] of iodine are present in 12.75 grams of [tex]CaI_2[/tex].

Answer:

18,200 is expressed in scientific notation as [tex]1.82 \times 10^4[/tex]

Explanation:

To write 18,200 using the scientific notation you have to divide it and multiply it by 10,000 (because 10,000 has 5 digits like 18,200) as follows:

[tex]\frac{18,200}{10,000} \times 10,000[/tex]

[tex]1.82 \times 10,000[/tex]

10,000 can be rewritten as [tex]10^4[/tex]. Therefore:

[tex]1.82 \times 10^4[/tex]

Answer: The mass of iron recovered is 17.5 grams

Explanation:

We are given a chemical compound having chemical formula of [tex]Fe_2O_3[/tex]

We know that:

Molar mass of iron (III) oxide = 159.7 g/mol

Mass of iron = 55.8 g/mol

We are given:

Mass of iron (III) oxide = 25 g

To calculate the mass of iron recovered in given amount of iron (III) oxide, we use unitary method:

From 159.7 grams of iron (III) oxide, mass of iron recovered is [tex](2\times 55.8)g[/tex]

So, from 25 grams of iron (III) oxide, mass of iron recovered will be [tex]\frac{(2\times 55.8)}{159.7}\times 25=17.5g[/tex]

Hence, the mass of iron recovered is 17.5 grams

The iron that will be recovered from 25 g of [tex]\bold{Fe_2O_3}[/tex] is

Ferric oxide is an organic compound with the chemical formula [tex]\bold{Fe_2O_3}[/tex]. It is one of the three main oxides of iron.

Given,

Mass of [tex]\bold{Fe_2O_3}[/tex] is 25 gram

Molar mass of iron oxide is 159.7

Mass of iron is 55.8 g

To calculate the amount of iron

From 159.7 g of ferric oxide, the amount of iron we found is [tex]55.8\;g \times 2[/tex]

So, from 25 grams of ferric oxide, the mass of iron recovered will be

[tex]\dfrac{55.8 \times 2}{159.7} \times25 = 17.5 g[/tex]

Thus, the mass of iron recovered is 17.5 g.

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2 LiI + Cl₂ → 2 LiCl + I₂

2 LiBr + F₂ → 2 LiF + Br₂

Each of the five reactions involve one halogen molecule (F₂, Cl₂, Br₂, and I₂) substituting the ion of another halogen (F⁻, Cl⁻, Br⁻, and I⁻).

Halogen atoms are found in group 17 of the periodic table. They are all non-metal elements. Each of the halogen atom will gain one electron to form an ion of charge -1. However, the tendency to do so decreases down the group.

Atoms of all four elements have the same effective nuclear charge of +7. However, F has the smallest radius. As a result, it has the strongest hold on electrons around it. Its ion F⁻ is more stable than ions of Cl, Br, or I. Similarly, its molecule F₂ is more reactive than Cl₂, Br₂, and I₂.

As a result, the stability of halogen molecules increases down the group:

The stability of halogen ions decreases down the group:

Cl₂ repaces F⁻ (from LiF) in first reaction. F₂ and Cl⁻ are produced. F₂ is less stable than Cl₂. Cl⁻ is less stable than F⁻.

Cl₂ replaces I⁻ (from LiI) in the second reaction. I₂ and Cl⁻ are produced. I₂ is more stable than Cl₂. Cl⁻ is more stable than I⁻.

Br₂ replaces Cl⁻ (from LiCl) in the third reaction. Cl₂ and Br⁻ are produced. Cl₂ is less stable than Br₂. Br⁻ is less stable than Cl⁻.

F₂ replaces Br⁻ (from LiBr) in the fourth reaction. Br₂ and F⁻ are produced. Br₂ is more stable than F₂. F⁻ is more stable than Br⁻.

I₂ replaces Br⁻ (from LiBr) in the fifth reaction. Br₂ and I⁻ are produced. Br₂ is less stable than I₂. I⁻ is less stable than Br⁻.

Based on the reactivities of the elements involved, 2LiI + Cl₂ → 2LiCl + I₂ and 2LiBr + F₂ → 2LiF + Br₂ reactions will form products that are more stable than the reactants.

Reactivity of any element is inversely proportional to the stability of the element. Because the stable element will not react quickly.

In the given question all the reactants are halogens except lithium and halogens are belongs from the 17th group of the periodic table.

                                          F₂ < Cl₂ < Br₂ < I₂

                                          F⁻ > Cl⁻ > Br⁻ > I⁻

Hence, the stable reactions are 2LiI + Cl₂ → 2LiCl + I₂ and 2LiBr + F₂ → 2LiF + Br₂.

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A hazardous chemical instantly discharging gas, pressure, and heat when subjected to pressure, heat, or high temperature is categorized under hazard class I explosives by the Department of Transportation.  

These are the explosives that possess the tendency to briskly detonate or conflagrate as an outcome of the chemical reaction. The explosives possess the tendency of generating pressures, temperatures, and speeds as leading to catastrophic destruction via force and/or of generating otherwise hazardous concentrations of light, heat, gas, sound, or smoke, all this resulting due to chemical reactions.  

D - are more organized

Answer: Are less organized

Explanation:

The formation of a solid has to do with a very ordered arrangement of molecules in a regular repeating pattern. The arrangement of molecules must be neat enough to allow close packing of the ordered arrangement. Ionically bonded species have a neat arrangement of oppositely charged ion pairs. This accounts for their abundant existence in the solid state. There is less order in the packing of covalent molecules as they as mostly held by weak intermolecular forces. Hence they exist mostly as liquids and gases.

Ice caps would float therefore providing insulation for aquatic life and ensuring they do not freeze due to the cool temperature.

The answer is D-Nitrogen(N).

Nitrogen has three unpaired valence electrons, therefore, it can form three covalent bonds.

Empirical Formula = C20 H60 HG1 S1 O4 (numbers should be in subscript)

Percent Composition =

MG = 43%

S = 56.8%

Answer:

Gas B: 5 liters at 10 °C

Explanation:

the warmer the container is the faster the molecules will move cause they aren't frozen and not able to move like Gas C: 5 liters at 40 °C.

Answer: Chemical Reactions, Acids, and Bases Unit Test

1. 24 mL of Mg burn in 32mL O2 to produce 56 mL of MgO

2. 92.4

3. Bonds of the reactants are broken, and bonds of the products are formed

4. The reaction rate decreases

5. in chemical equilibrium

6. The equilibrium shifts to the right and more products are formed

7. the I ion and the positive end of a water molecule

8. Less than 0 degree Celsius

9. Greater than

10. Solubility

11. feels slippery

12. MgCl2 and H2O

13. accept a proton and become NH4+

14. stay about the same

15. electrolyte

These are the answers I put for the short answers:

16. The double-replacement is KBr+. The resulting compound is AgNO3+AgBr

17. The ion that is formed is Br. The bromine gets reduced

18. Buffer solution is a solution that is resistant to large changes in pH

19. The peaks are called the activation energy. It is energy used to get the reaction going.

20. It is supersaturated

21. According to the figure above detergent is a base

Part 2: These are the answers that I put as well

1. 4Fe+3O2=2Fe2O3  3:2

2. 1.31M

3. 300mg of water

4. 60.46 kJ would be absorbed during the reaction

The answer is; A

During a hot day, the land heats up faster than the waters. The air on land becomes warm and less dense fast and begin to rise in the atmosphere. The air on the ocean with is still cooler and denser moves in to replace the rising on land air. This causes a sea breeze. The sea breeze carries with it, moisture. The hotter the day the higher the humidity. When the air goes inland, it causes precipitation when it rises,  cool, and condenses.

Answer:

I got it Right

Explanation:

In Study Island

The electrostatic attraction between positively charged nuclei and negatively charged electrons permits two atoms to be held through either a covalent bond, where the electrons are shared between atoms, or an ionic bond, where one atom donates or accepts an electron from the other, creating ions which are attracted to each other.

The electrostatic attraction between positively charged nuclei and negatively charged electrons allows two atoms to be held together through what is known as a covalent bond or an ionic bond. In a covalent bond, these forces of attraction are between the nuclei of a molecule's atoms and pairs of electrons between these atoms. For instance, in an oxygen molecule O₂, the electrons are equally shared between the atoms, establishing a covalent bond.

On the other hand, in an ionic bond, a atom donates or accepts an electron resulting in a positively or negatively charged atom, termed as an ion. For example, a sodium (Na) atom can donate its 2s electron to a chlorine (Cl) atom. This results in a positively charged Na+ ion and a negatively charged Cl- ion. The electrostatic attraction between these charged ions creates an ionic bond and forms a salt molecule (NaCl).

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The correct answer is option C, that is, cohesion and adhesion.  

The molecules of water stay near to each other via cohesion, that is, the combined activity of hydrogen bonds amongst the molecules of water. The property of cohesion assists the plant to move water upwards from the root via the xylem towards the leaf.  

At the same time, adhesion between the molecules of water to the cell walls of the plant assists to counteract gravity while water is conducted from the roots to the leaves. Thus, both the cohesion and the adhesion produces a capillary action, which keeps the molecules of water interacting with each other and conducting via the plants out to the cells of the leaf.  

The correct answer is D

Answer:

It was frozen.

Explanation:

A substance may undergo any chemical change in its nature in all the given cases except when it is frozen.

A) during heating there is chances that it undergoes decomposition . Like if calcium carbonate is heated it converts to calcium oxide and carbon dioxide.

B) When a compound is hit with a hammer there is chance of its chemical decomposition.

C) If a compound is placed in a salt solution it may react with the salt or water.

D) However freezing is purely a physical process, where contact with any other compound or any chance of chemical decomposition is not possible.

Drinking one standard drink will increase your BAC by about 0.02 (remember this can depend on the factors mentioned above). As your BAC rises, so does your risk of being involved in a crash. This is why drivers with an open licence have to keep under a BAC of 0.05.

Final answer:

The correct answer is "move faster". When a solid is heated, the particles that compose it move faster due to an increase in their average kinetic energy. The solid may expand overall, but the individual particles do not get bigger, lose mass, or slow down. The temperature rise is an indication of the increased vibrational motion of the particles within the solid.

Explanation:

When you heat a sample of a solid, the particles that make up the solid move faster. This happens because heating a substance increases the amount of thermal energy, which then increases the average kinetic energy (KE) of the particles. At a microscopic level, a solid consists of molecules and atoms vibrating quickly in place when hot, and moving slowly when cold, without any chemical reaction or phase change like melting or vaporizing. In a solid, these particles are in a constant state of vibration, and as they are heated, they gain energy and vibrate more quickly, which we interpret as an increase in temperature.

As the temperature rises, it's an excellent approximation that solids expand in each dimension by a specific fraction, assuming no constraints on their expansion. However, the particles themselves do not get bigger, lose mass, or slow down when heated. Instead, the increase in temperature may cause the solid to expand overall, while the proportions of the solid remain constant. This is because the interaction potential curve between particles is usually asymmetric, becoming less steep at greater distances and showing an increase in equilibrium particle-particle distance when the substance is heated.

If we consider endothermic processes like melting, the added heat increases the speed of the molecules causing them to move faster. In contrast, exothermic processes like freezing decrease the speed of the molecules causing them to move slower. Hence, the correct answer is that the particles move faster when a solid is heated.

metals are malleable, which means they can be flatten to sheets.

Also metals are ductile , which means they can be made into thin wire.

The metals are malleable because the free flowing atoms act as a lubricant and allow the metal atom layer to roll over each other.

Answer:

Metals are NOT malleable because of lubricants.

The statement is FALSE.

Explanation:

Malleability is the ability of a material to bend while under pressure (compressive stress). A o malleable metal is one which can be hammered, rolled or  flattened into thin sheets. Gold, iron, aluminium, copper, silver and lead are types of malleable metals.

Cheers!

Answer:

2500

Explanation:

The answer is letter D. Reactants, Products

The correct answer is option D, that is, increased coastal flooding.  

The change in climate is enhancing the frequency of coastal flooding, comprising floods just from tides. The combination of melting of ice into the oceans and expansion of water as the ocean has warmed has increased the level of the sea up to about seven inches since 1900, and the elevation is on the rise.  

From 2005 to 2015, the average number of floods has doubled along the stretch of coast from Florida to North Carolina. The flooding will become even more usual in the coming time as the concentration of greenhouse gases discharged into the atmosphere will increase the levels of the sea in years to come.