Why does a metal spoon left on a bowl of hot soup become warm?

Answer:

There are 55, 49 g of CaCl2

Explanation:

We calculate the weight of 1 mol of CaCl2:

Weight CaCl2=Weight Ca + 2x(Weight Cl)= 40,08g+ 2x 35, 45g=110,98 g/mol

1000ml-----2 mol of CaCl2

250ml------x= (250 ml x 2 mol of CaCl2)/1000ml= 0,5 mol of CaCl2

1mol -----110,98g

0,5mol ---x= (0,5molx110,98g)/1 mol= 55,49 g

Answer:

asthma

Explanation:

asthma is a respiratory problem which causes difficulty in breathing which is usually because of allergic reactions or hypersensitivity to something else. so as it's written in the question that materials are emitted from vehicles, there is a big chance that they will cause an allergic reactions (asthma) in Steve.

1) The mass of iron III oxide is 3.92 g and the mass of water is 1.32 g

2) The mass of the Mg is  19.44 g

3) The mass of calcium phosphate is 109 g

What is stoichiometry?

1) The equation is;

[tex]2Fe(OH)_3 - > Fe_2O_3 + 3H_2O[/tex]

Number of moles of iron III hydroxide

Moles = Mass/Molar mass

= 5.25 g/107 g/mol

= 0.049 moles

2 moles of iron III hydroxide produces 1 mole of iron III oxide

0.049 moles of iron III hydroxide produces 0.049 moles  * 1 mole/2 moles

=0.0245 moles

Mass iron III oxide = 0.0245 moles * 160 g/mol

= 3.92 g

2 moles of  of iron III hydroxide produces 3 moles of water

0.049 moles of iron III hydroxide produces 0.049 moles * 3 moles/ 2 moles

= 0.0735 moles

Mass of water = 0.0735 moles * 18 g/mol

= 1.32 g

2) Moles of magnesium fluoride = 50 g/62 g/mol

= 0.81 moles

[tex]Mg + F_2 -- > MgF_2[/tex]

1 mole of Mg produces 1 mole of magnesium fluoride

x moles of Mg produces 0.81 moles of magnesium fluoride

x = 1 * 0.81/1

= 0.81 moles of Mg

Mass of the Mg = 0.81 moles  * 24 g/mol

= 19.44 g

3) [tex]3CaO + P_2O_5 --- > Ca_3(PO_4)_2[/tex]

Moles of calcium oxide = 100 g/56 g/mol

= 1.79 moles

Moles of phosphorus pentaoxide = 100 g/284 g/mol

= 0.35 moles

If 3 moles of calcium oxide reacts with 1 mole of phosphorus pentaoxide

1.79 moles of calcium oxide reacts with  1.79 * 1/3

= 0.596 moles

Thus phosphorus pentaoxide is the limiting reactant

1 mole of phosphorus pentaoxide produces 1 mole of calcium phosphate

0.35 moles of phosphorus pentaoxide produces 0.35 moles of calcium phosphate

Mass of calcium phosphate produced = 0.35 moles * 310 g/mol

= 109 g

Answer:

32km/hr

Explanation:

The question asks to calculate the average speed for a boat.

Mathematically, the average speed is the total distance divided by the total time

Let’s get the total distance traveled:

That would be 70km + 26km = 96km

Now the total time taken would be 3 as the boat did not move at all for an hour.

The average speed is thus 96/3 = 32km/hr

Answer:

V₂ = 18.13 L

Explanation:

Given data:

Mole of gas = 1 mol

Initial temperature = 273 K

Initial pressure = 1 atm

Final volume = ?

Final temperature = -41°C (-41+273 = 232 K)

Final pressure = 805 mmHg (805/760 = 1.05 atm)

Solution:

First of all we will calculate the initial volume of gas.

PV = nRT

V = nRT/P

V = 1 mol × 0.0821 mol.L/atm.K × 273 K / 1 atm

V = 22.4 L/atm / 1 atm

V = 22.4 L     ( initial volume)

Now we will determine the final volume by using equation,

P₁V₁/T₁ = P₂V₂/T₂

P₁ = Initial pressure

V₁ = Initial volume

T₁ = Initial temperature

P₂ = Final pressure

V₂ = Final volume

T₂ = Final temperature

Now we will put the values.

V₂ = P₁V₁ T₂/ T₁ P₂  

V₂ = 1 atm × 22.4 L ×  232 K / 273 K × 1.05 atm

V₂ = 5196.8 atm .L. K / 286.65 atm.K

V₂ = 18.13 L

The correct answer is a reference point.

To determine whether or not an object moves, one must have a reference point. A reference point is a fixed point that is used to determine if an object has changed its position. Without a reference point, it is impossible to ascertain whether an object is moving or at rest because motion is relative. An object may appear to be moving when observed from one reference point, but it could be stationary when observed from a different reference point.

Distance alone does not indicate motion; it only specifies the amount of space between two points. Displacement is the change in position of an object, which requires a reference point to be measured. Standard units are necessary for quantifying distance or displacement but do not themselves indicate motion.

In summary, while distance, displacement, and standard units are important for describing the motion of an object, a reference point is the fundamental requirement to determine whether an object is moving.

Answer: V = 5.1 L

Explanation: To find the new volume, we will use the formula of Combined Gas Law and derive V2. We also need to convert first the temperature in Kelvin and convert torr to atm ( 1 atm = 760 torrs ).

Solution attached.

Answer: your answers are between d or b

Explanation:

The Cosmic Microwave Background (CMB), a remnant heat from the Big Bang, supports the theory's predictability. Its discovery provided strong evidence for the beginning of the universe as theorized in the Big Bang Theory.

The predictability of the Big Bang Theory was proven by the presence of the Cosmic Microwave Background (CMB). The CMB refers to the thermal radiation that is presumed to be leftover from the 'Big Bang' – the explosion that marked the beginning of the universe approximately 13.8 billion years ago. This residual heat was predicted by the Big Bang Theory, and its eventual discovery provided strong evidence supporting the theory. Thus, it is the CMB that validated the predictability of the Big Bang Theory more than the other phenomena listed in your options.

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Answer:

73818.9

Explanation:

for an approximate result, multiply the speed value by 197

Answer: A. Larry must have grabbed a concave lens since the legs look smaller.

Explanation:

I'm not sure. I did some research and it seems that this is the correct one because, universe today.com said; "A concave lens is a lens that possesses at least one surface that curves inwards. It is a diverging lens, meaning that it spreads out light rays that have been refracted through it. A concave lens is thinner at its centre than at its edges, and is used to correct short-sightedness (myopia)." and passmyexams.co.uk said; "Convex lenses are thicker at the middle. Rays of light that pass through the lens are brought closer together (they converge). A convex lens is a converging lens.   When parallel rays of light pass through a convex lens the refracted rays converge at one point called the principal focus.  The distance between the principal focus and the centre of the lens is called the focal length." and so, this lead me to believe that the answer is; A. Larry must have grabbed a concave lens since the legs look smaller.

Answer:

When heat is added to a substance the molecules and atoms vibrate faster. As atoms vibrate faster the space between atoms increases. The motion spacing of the particles determines the state of matter of the substance. The end result of increased molecule emotion is that the object expands and takes up more space.

Answer:

313, 6grams of H3PO4

Explanation:

We calculate the weight of 1 mol of H3PO4:

Weight 1 mol H3PO4= (Weight H)x3+ (Weight P)+(Weight 0)x4  =1gx3+31g+16gx4

Weight 1 mol H3PO4=98 g /mol

1 mol-----98 grams H3PO4

3,2mol----x= (3,2molx 98 grams H3PO4)/ 1mol=313,6 grams H3PO4

Answer:

in a solid particles or still but as it gets hot the particles will move around rapidly

As a solid heats to its boiling point, it undergoes phase changes from solid to liquid to gas. At each stage, the particles' movement changes from fixed vibrations to free movement. These changes occur at constant temperatures known as the substance's melting and boiling points.

The movement of particles in a solid substance as it is heated to its boiling point involves different states of matter: the solid, liquid, and gas phases. In the solid phase, the particles of the substance are closely packed together and vibrate about fixed positions. As the temperature of the solid rises due to the heat, the vibrations of the particles increase. Upon reaching the melting point, the solid begins to transform into a liquid, a process known as melting.

The temperature remains constant during this phase transition until the entire solid has melted. In the liquid phase, the particles are not as closely packed as in a solid and can move more freely. As the temperature continues to rise, the liquid will eventually reach the boiling point, where it starts transforming into a gas in a process called vaporization. During this phase change, the temperature again remains constant until all the liquid has become a gas.

In the gas phase, the particles move most freely, colliding with each other and filling the available space. The behavior of these phase transitions is determined by the substance's unique melting and boiling points, which are affected by the environment's pressure. Phase changes also involve changes in the amount of heat in the substance, with heat absorbed during melting and vaporization, and released during condensation and freezing.

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Answer:

Find the Molar mass of each, find the limiting reagent, if there is one, and then multiply by .94. This is the quick way.

Explanation:

Answer:

160.4K

Explanation:

Given parameters:

Initial volume of gas = 2.9L

Initial pressure of gas = 5atm

Initial temperature = 50°C

Final volume = 2.4L

Final pressure of gas= 3atm

Unknown:

Final temperature = ?

Solution:

To solve this problem, we have to apply the combined gas laws.

Mathematically, the law is expressed as;

                  [tex]\frac{P_{1}V_{1} }{T_{1} } = \frac{P_{2}V_{2} }{T_{2} }[/tex]

where P₁ is the initial pressure

           V₁ is the initial volume

           T₁ is the initial temperature

          P₂ is the final pressure

          V₂ is the final volume

          T₂ is the final temperature

Since T₂ is the unknown, we must solve for it.

 convert T₁ from °C to K;

       T₁ = 273 + 50 = 323K

Now insert the parameters;

     [tex]\frac{5 x 2.9}{323} = \frac{3 x 2.4}{T_{2} }[/tex]

[tex]T_{2}[/tex] = 160.4K

According to Boyle's Law, when the volume of a gas decreases at constant temperature, the pressure of the gas increases. Using the formula P1V1 = P2V2, we can calculate the final temperature of the gas. In this case, the final temperature would be approximately 29.0 °C.

According to Boyle's Law, when the volume of a gas decreases at constant temperature, the pressure of the gas increases. This is expressed mathematically as P1V1 = P2V2, where P1 and V1 are the initial pressure and volume, and P2 and V2 are the final pressure and volume.

In this case, the initial pressure is 5.0 atm, the initial volume is 2.9 L, the final volume is 2.4 L, and the final pressure is 3.0 atm. Plugging these values into the equation, we can solve for the final temperature. Rearranging the equation to solve for temperature gives T2 = (P2V2/T1) * (V1/P1).

Using the given values, we find T2 = (3.0 atm * 2.4 L) / (5.0 atm * 2.9 L) * (50.0 °C). Solving this equation gives T2 ≈ 29.0 °C.

Answer:

78 moles of the solute

Explanation:

From the question;

We want to determine the number of moles needed

We need to know that;

Molarity = Number of moles ÷ Volume

Therefore;

Number of moles = Molarity × Volume

Hence;

Number of moles = 6.50 M × 12.0 L

                             = 78 moles

Thus, the moles of the solute needed is 78 moles

Answer:

The molar mass of N5O9

is 214.0245g/mol

Explanation:

To solve this problem, we need to know each number of mole of each element present in the compound

N has 5 moles

O has 9 moles

Then, we multiple each number of mole by its number of mass of each element present

N - 14.0067

O - 15.999

Multiplying by mole

N - 5 * 14.0067 = 70.0335

O - 9 * 15.999 = 143.991

Therefore,

Molar mass of N5O9 = 70.0335 + 143.991

= 214.0245g/mol

Answer:

The mass of liquid comes out to be 82 g.

Explanation:

Given density of liquid = 1.64 g/mL

Given volume of liquid = 50 mL

The relation between density and volume is shown below

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

Mass of liquid = [tex]1.64 \textrm{ g/mL}\times 50 \textrm{ mL} = 82 \textrm{ g}[/tex]

Mass of 50 mL liquid = 82 g

Answer:

Different atmospheric pressure. When there is a different atmospheric pressure, air moves from the higher pressure to the lower pressure area which results in what you call WIND but can result in various speeds and pressure.

Hope this helped and if it did, please give my answer a brainliest.

Answer:

Wind is caused by differences in the atmospheric pressure.

Explanation:

When a difference in atmospheric pressure exists, air moves from the higher to the lower pressure area, resulting in winds of various speeds.

Answer:OK. One of the properties of an ionic compound is that it conducts a current in aqueous (water) solution.

The ionic compound is held together by virtue of the opposing charges; plus and minus. In water, they may just crumble away into solution! But if you Heat a solid piece of a salt, an ionic compound, it takes a great deal of Energy! So look at Compound Y.

WOW! 455°C to melt. That is high. To boil it? 1550°C. That is very high! Especially compared to compound X!

It melts at -90°C, and boils at 82°C. So it is X that is your molecular compound, one of covalent bonding, or sharing electrons, VERY different than the ionic compound held together by opposing charges.

Explanation:

Ionic compounds consist of ions held together by electrostatic attraction, while molecular compounds are formed by the sharing of electrons between nonmetal atoms.

An ionic compound consists of ions held together by electrostatic attraction, while a molecular compound consists of molecules held together by covalent bonds. Ionic compounds typically consist of a metal cation and a nonmetal anion, such as NaCl (sodium chloride). Molecular compounds, on the other hand, are formed by the sharing of electrons between two or more nonmetal atoms, such as H2O (water).

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The questions listed above relate to Earth systems and their interactions, especially in relation to climate change and global warming.

The questions listed above relate to the study of Earth systems and their interactions:

Scientists researching climate change and global warming focus on these aspects to understand the impact on the water cycle and life on Earth.

Scientists consider various research questions about how global warming affects the water cycle, investigating the effects on evaporation, precipitation, ocean currents, and ecosystems.

When considering how global warming may impact the water cycle, and thus life on Earth, scientists are likely to focus on a wide range of research questions. These could include questions such as:

In an endothermic reaction products are HIGHER than reactants in potential energy and LESS stable.

Explanation:

Energy is input into the reaction in an endothermic reaction. This means the products are of a higher energy level than the reactants. Therefore the reaction increases Gibb's free energy and reduces entropy. Remember in thermodynamic stability involves an increase in entropy and a decrease in Gibbs free energy. Therefore the products are less stable than the reactants. This is why endothermic reactions do not occur spontaneously like exothermic reactions.

Answer:

your answer is D -_- bc they want the approximate

Answer:

Option A. 3 × 10^21 molecules

Explanation:

From Avogadro's hypothesis, 1mole of any substance contains 6.02x10^23 molecules. This means that 1mole of H20 also contains 6.02x10^23 molecules.

1mole of H2O = (2x1) + 16 = 2 + 16 = 18g

If 1mole(i.e 18g) of H2O contains 6.02x10^23 molecules,

Therefore 0.1g of H2O will contain = (0.1 x 6.02x10^23) /18 = 3 x 10^21 molecules

Answer:

  Ocean water taken from the surface of the ocean

Explanation:

Attached is a plot of ocean salinity vs. depth. It shows the highest salinity ocean water is surface water. A world-wide map of ocean salinity shows the highest salinity to be in mid-latitude regions in the middle of the ocean. Water near the North Pole has lower salinity than that for lower latitudes.

Probably the main reason for higher salinity at the surface is the high evaporation rate of water there, leaving behind the salt.

Answer:

The correct answer is D) The volume of the gas will increase.

Explanation:

According to Charles's Law, at constant pressure, as the temperature (T) of a gas increases, the volume (V) increases and vice versa. This is observed according to the formula:

V1 / T1 = V2 / T2

Answer: Addition Property of Equality

Explanation:

The addition property of equality says that if we add same value or quantity on both sides of an equation, the values on both the sides remain equal. Consider an equality a = b. Addition property of equality is a + x = b + x. Add the same number to both the sides of an equation.

Answer:

Explanation:

Mixed groups are groups on the periodic table that contain more than one class (as in metals, non-metals or metalloids) of elements. Groups 13 to 16 form the mixed groups of the periodic table because they contain at least two different classes of elements.

However, groups 14 and 15 contain more classes (three classes) than groups 13 and 16 (two classes). Group-14 contains metals (examples include tin), non-metals (examples include carbon) and metalloids (examples include silicon) while group-15 also contains metals (such as bismuth), non-metals (such as nitrogen) and metalloids (such as arsenic). Whereas group 13 and 16 only contain two classes of elements; group-13 contains metalloid (boron) and metals (such as aluminium) while group-16 contains metalloids (such as tellurium) and non-metals (such as oxygen).

Final answer:

Groups 14 and 15 exemplify a broad range of chemical behaviors, including metal, nonmetal, and metalloid elements, making them more representative of mixed groups than Groups 13 and 16.

Explanation:

Groups 14 and 15 are better representatives of mixed groups than groups 13 and 16 because they include both metals and nonmetals, thus displaying a wider range of physical and chemical properties. Groups 14 and 15, which include the carbon group and the pnictogens, respectively, have elements that are essential to life and industry and exhibit diverse chemical behaviors. Lewis structures show that these groups can form neutral compounds with four and three bonded atoms, respectively, reflecting a trend where the number of bonds decreases across the period. In contrast, Group 13 elements are largely metals and Group 16 elements are largely nonmetals or metalloids, showing less diversity.

The advantage in using a simple machine is to reduce the amount of work needed to move on object

Option A

Explanation:

A Simple machine is a device with less moving parts used to change motion and force to perform work. Some of the simple machines are the inclined plane, lever, wedge, wheel and axle, pulley, and screw which we all use in our daily life.

These simple machines make our work fast and accurate and also does not require much effort for the work to be done. In other words, we can tell simple machines make our work simpler. For eg: If we take the simple machine wheel and axle, in a bicycle, instead of moving the whole wheel, if we apply force on the pedals, the wheel starts moving. Thus, only less effort is required to move an object.

Answer:

The second one is the CORRECT answer.

Explanation:

Answer:

Baking a cake is a chemical change

Explanation:

The fourth energy level of an atom can accommodate a maximum of 32 electrons, calculated with the formula 2n^2 for the fourth level (n=4), which results in 2 * 16 = 32.

The fourth energy level of an atom can hold a maximum of 32 electrons. This is because the number of electrons that can fit in a given energy level is determined by the formula 2n2, where n is the principal quantum number corresponding to the energy level. For the fourth energy level (n=4), we calculate 2 * 42 = 2 * 16 = 32. Therefore, there are 32 positions for electrons in the fourth energy level, which means 32 electrons can be accommodated when this level is fully occupied.

It's important to note that energy levels are like concentric circles around the nucleus where electrons reside. The fourth energy level is the furthest out compared to the first three levels and therefore, electrons located here will have the most energy. Each orbital within these levels can hold a maximum of two electrons.