Match each pH value with the correct description. 7, 2, 8, 13, and 6 :)

1. strong acid

2. weak acid

3. strong base

5. neutral

Accuracy refers to the closeness of a measured value to a standard or known value. Precision is independent of accuracy. You can be very precise but inaccurate.

Answer:

Both terms are related and they are really important in the science field to measure how successful can be an experiment.

First, the accuracy is the relation to express how close is the value that I measure in an experiment from a real value that it has been already proved.

For example: I measure the volume of a soda can in my lab and I found that this soda can has 235 mL inside but the packing says that has 230 mL. So it means that my measure data it is not accurate.

Thus, the accuracy is important because gives me validity of my designed experiment.

Second, the precision is the relation between my datas and how far are they from each other.

For example: Taking again the example of the soda can, I was in the lab measuring the volume and I made it 3 times. My datas were: 235 mL, 220mL, and, 210 mL. So it means that my measures are far from each other so it is not precise.

Precision is important because gives reliability to the experiment.

There is also mathematical approximations to measure accuracy and precision, the accuracy can be measure finding the error and the precision can be measure by a standard deviation that means how far are my datas from the average.

Final answer:

During a flood, the water table rises, causing the zone of saturation to expand and the zone of aeration to diminish as the subsurface becomes increasingly waterlogged, which can have varying impacts on the ecosystem.

Explanation:

During a flood, the water table, zone of saturation, and zone of aeration undergo significant changes. The water table is the boundary between the zone of saturation, where the pore spaces in the ground are fully saturated with water, and the zone of aeration, where the pores are mainly filled with air. When a flood occurs, excessive rainwater and overflowing water bodies lead to an increase in ground saturation, causing the water table to rise temporarily. In such circumstances, the zone of saturation expands while the zone of aeration diminishes because more of the subsurface becomes waterlogged.

Flooding can also have various effects on the surrounding ecosystems and landscape. Sudden changes in water table levels can lead to soil saturation, impacting plant survival and depending on their adaptations to waterlogged conditions. Ecosystems dependent on stable groundwater levels, such as riparian areas near rivers, may experience stress or damage from the altered hydrological dynamics caused by flooding.

Answer is: B) The cart will move to the left.

A newton (N) is the International unit of measure for force.

One newton is the force needed to accelerate one kilogram of mass at the rate of one metre per second squared in direction of the applied force.

The cart will move to the left by the force of 2 newton.

F(cart) = 7 N - 5 N.

F(cart) = 2 N to the left.

In the given chemical reaction, 3.0 moles of hydrogen will be produced from 2.0 moles of aluminum.

In the given chemical reaction:

2Al + 3H2SO2 ⟶ 3H2 + Al2(SO2)3

We can see that 2 moles of aluminum (Al) react to produce 3 moles of hydrogen (H2). Therefore, if we start with 2.0 mol of aluminum, we can calculate the moles of hydrogen produced as follows:

2.0 mol Al x (3 mol H2 / 2 mol Al) = 3.0 mol H2

So, 3.0 moles of hydrogen will be produced from 2.0 moles of aluminum.

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For the chemical reaction 2Al + 3H₂SO₄ rightarrow Al₂(SO₄)₃ + 3H₂, 2.0 moles of aluminum will produce 3 moles of hydrogen gas.

Moles of hydrogen (H₂) will be produced from 2.0 mol of aluminum (Al) in the reaction with sulfuric acid. According to the balanced chemical equation 2Al + 3H₂SO₄ rightarrowAl₂(SO₄)₃ + 3H₂, 2 moles of aluminum produce 3 moles of hydrogen gas.

Using stoichiometry, we can set up a ratio from the coefficients in the balanced equation: 2 moles of Al : 3 moles of H₂. Therefore, if we start with 2.0 moles of Al, we will produce 3 moles of H₂.

Here's the calculation:
(2.0 moles Al)*(3 moles H₂ / 2 moles Al) = 3 moles H₂.

Answer is: beryllium fluoride has sp hybridization.

Beryllium (Be) is metal from group 2 and fluorine (F) is nonmetal from group 17.

Electron configuration of beryllium atom: ₄Be: 1s² 2s².

Electron configuration of fluorine atom: ₉F 1s² 2s² 2p⁵.

In beryllium, one electron from 2s orbital gets excitted to the level of 2p orbital; s and p orbital are hybridized and form two sp-hybridised  orbitals arranged in a linear shape.

Two fluorine atoms come closer to beryllium atom and sp hybridised orbitals of Be and p orbital of F get overlapped with each other and make bonds.

The hybridization of orbitals in beryllium fluoride (BeF2) is sp hybridization, resulting in a linear molecular geometry with a bond angle of 180 degrees due to the two sp hybrid orbitals formed from the 2s and 2p orbitals of beryllium.

The hybridization of orbitals in beryllium fluoride, BeF2, is sp hybridization. Beryllium in its ground state has a 1s22s2 electron configuration, and to form bonds, one of the 2s electrons is promoted to the empty 2p orbital. After this, the 2s and one of the 2p orbitals hybridize to form two new orbitals that are identical in energy and shape, which are called sp hybrid orbitals. These hybrid orbitals in BeF2 ensure the molecule has a linear structure with a bond angle of 180 degrees.

A Lewis structure of BeF2 shows a beryllium atom with two single bonds to two fluorine atoms, each having three lone pairs of electrons. The linear geometry of BeF2 is maintained because of the two sp hybrid orbitals pointing in opposite directions away from the central beryllium atom to form bonds with the fluorine atoms.

2VCl2 + 3Cl2 -> 2VCl5

Reactants: 2VCl2 and 3Cl2

Product: 2VCl5

To balance the equation, set up a chart with the reactants and products on separate sides. On one side should be V - 1 and Cl - 4 with a line and on the right side should be V - 1 and Cl - 5.

The numbers correspond with the subscripts. To balance, use the biggest compound (VCl5) and multiply that by 2 in order to get an even number for both of 2 and 10. For the reactants, you now need to multiply to get corresponding amounts.

Hope this helps!

Answer: Reactants: 2VCl2 and 3Cl2; product: 2VCl5

Explanation:

Bromine is one of the members of the halogen family of elements. The other members belonging to the same family comprise chlorine, fluorine, and iodine. Like the other members of the family, bromine comprises seven electrons in its outermost shell and is very reactive.  

Bromine can be witnessed in various salt compounds with alkali metals. Like all reactive elements, bromine is never found solitary in nature. It always forms a part of a compound with other elements.  

Your answer is strontium

Molar mass of CHCl3 is

sum of atomic mass of all the atoms in it.

= C + H + 3 Cl

= 12.0107 + 1.008 + 3 (35.453) = 2.0107 + 1.008 +   106.359

= 119.38 g/mol

Molar mass of CHCl3 is 119.38 g/mol

Carbon Dioxide is the most common reason water becomes full of alkaline. Hopefully  I could help :)

Im pretty sure austin texas is the closest place to the epicenter

The epicenter is the point on the Earth's surface directly above where an earthquake or underground explosion originates. The nearest city to the epicenter will likely experience significant effects of the event. For example, San Francisco was near the epicenter of the 1906 earthquake.

The question does not provide a specific location or event, which makes it difficult to give a definite answer. In general, the term epicenter is used in geology, specifically in the context of earthquakes. It refers to the point on the Earth's surface directly above the point where an earthquake or other underground explosion originates—this point is known as the focus or hypocenter. Usually, the city near the epicenter of an earthquake will most likely experience the strongest shaking and highest degree of damage.

For example, if we were discussing the 1906 San Francisco earthquake, then San Francisco would be the city near the epicenter.

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Means that the African continent was once in the higher latitudes, and in contact with Antarctica, where glaciers form due to the low temperatures in the poles. The continent drifted over time due to tectonic plate movement. Continental drift is powered by the convection current in the mantle of the earth.

the right equation is 2NH3 -> N2+3H2

Answer:

No, it is:

[tex]2NH_3\rightarrow N_2+3H_2[/tex]

Explanation:

Hello,

In this case, all the given equation could be simplified by a factor of two to yield:

[tex]\frac{4}{2} NH_3 \rightarrow \frac{2}{2} N_2+\frac{6}{2} H_2[/tex]

Therefore, the answer is no, so it the lowest one is:

[tex]2NH_3\rightarrow N_2+3H_2[/tex]

Regards.

George Johnstone Stoney

George Johnstone Stoney

Charles law states a proportional relationship between volume and temperature.

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

V1= 100mL=0.1L

V2=400mL=0.4L

T1=80'c+273=353K

T2=?

T2=1412K-273=1139'C

the mass of ice taken = 10 g

the mass of water = 250 g

initial temperature of water = 20 C

the final temperature of water = 16. 8 C

specific heat of water = 4.18 J/g*K

the heat absorbed by ice to melt = heat loss by water

heat loss by water = mass X specific heat of water X change in temperature

heat loss by water = 250 X 4.18 X (20-16.8) = 3344 Joules

heat gained by ice = 3344 J

heat gained by ice = enthalpy of fusion X moles of ice

moles of ice = mass / molar mass = 10 / 18 = 0.56 moles

enthalpy of fusion = 3344 / 0.56 = 5971.43 J / mole

Answer is: copper (Cu).

Gold (Au) and silver (Ag) are noble metals and fall into the transitional metal family on the periodic table in group number 11.

Group 11 is also known as the coinage metals, due to their former usage.

Copper, silver and gold all occur naturally in elemental form.

Copper has atomic number 29, it has 29 protons and 29 electrons.

Electron configuration of copper atom: ₂₉Cu [Ar] 3d¹⁰ 4s¹.

Copper (Cu) is higher in activity series than silver and gold, so copper lose electron and silver gain electrons.

The answer is 2

2H2 + 2O2 -2H2O

2 H2 + 1 O2 = 2 H2O

B. 2 is the correct option

Answer:

Lithium has an atomic number Z of 3, so by definition, it has 3 protons. Hence, neutral lithium atoms must contain 3 electrons.

Explanation:

A neutral atom of lithium contains 3 electrons.

The number of electrons in a neutral atom is equal to its atomic number. The atomic number of an element represents the number of protons in its nucleus, and since atoms are electrically neutral (having no net charge), the number of electrons in the atom is also equal to the number of protons.

For lithium (Li), you can find its atomic number on the periodic table, which is 3. This means that lithium has 3 protons in its nucleus, and therefore, it also has 3 electrons to balance the positive charge of the protons. In a neutral atom, the number of electrons equals the number of protons, making lithium, with its 3 electrons, an electrically neutral atom.

To learn more about electrons, here

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Answer: The roll of lead (II) nitrate is that it is a limiting reactant of the reaction.

Solution : Given,

Molarity of [tex]FeCl_3[/tex] = 0.1 M

Volume of [tex]FeCl_3[/tex] = 50.0 ml = 0.05 L     (1 L = 1000 ml)

Molarity of [tex]Pb(NO_3)_2[/tex] = 0.1 M

Volume of [tex]Pb(NO_3)_2[/tex] = 50.0 ml = 0.05 L

First we have to calculate the moles of [tex]FeCl_3[/tex] and [tex]Pb(NO_3)_2[/tex].

[tex]\text{ Moles of }FeCl_3=\text{ Molarity}\times \text{ Volume in L}[/tex]

[tex]\text{ Moles of }FeCl_3=(0.100M)\times (0.05L)=0.005moles[/tex]

[tex]\text{ Moles of }Pb(NO_3)_2=\text{ Molarity}\times \text{ Volume in L}[/tex]

[tex]\text{ Moles of }Pb(NO_3)_2=(0.100M)\times (0.05L)=0.005moles[/tex]

The balanced chemical reaction is,

[tex]2FeCl_3+3Pb(NO_3)_2\rightarrow 2Fe(NO_3)_3+3PbCl_2[/tex]

From the balanced chemical equation, we conclude that

3 moles of lead nitrate react with 2 moles of ferric chloride.

Thus 0.005 moles of lead nitrate react with [tex]=\frac{2}{3}\times 0.005=0.0033[/tex] moles of ferric chloride.

Moles of ferric chloride will be left unreacted = 0.005 - 0.0033 =0.0017 moles

Limiting reagent is the reagent in the reaction which limits the formation of product.

Excess reagent is the reagent in the reaction which is in excess and thus remains unreacted.

Therefore, in the given reaction, lead nitrate is the limiting reagent and ferric chloride is the excess reagent.

Answer: iron (III) chloride is the excess reactant in the reaction.

Explanation:

i just did the assignment

Answer:

The hydrogen produces the smaller amount of ammonia.  

Step-by-step explanation:

We are given the masses of two reactants, so this is a limiting reactant problem.

We know we will need a balanced equation with masses and molar masses, so let’s gather all the information in one place.  

M_r:      28.02   2.016     17.03

                 N₂  +  3H₂ ⟶ 2NH₃

Mass/g:   70.0    7.00

1. Calculate the moles of N₂ and H₂

Moles N₂ = 70.0 × 1/28.02  

Moles N₂ = 2.498 mol N₂  

Moles H₂ = 7.00 × 2.016  

Moles H₂ = 3.472 mol N₂  

=====

2. Calculate the moles of NH₃ from each reactant

From N₂:

The molar ratio is 2 mol NH₃/1 mol N₂

Moles of NH₃ = 2.498 × 2/1

Moles of NH₃ = 4.996 mol NH₃

From H₂:

The molar ratio is 2 mol NH₃/3 mol H₂  

Moles of NH₃ = 3.472 × 2/3  

Moles of NH₃ = 4.139 mol NH₃

======  

3. Identify the limiting reactant

The limiting reactant is H₂, because it produces fewer moles of NH₃.

Answer: Sedimentary rocks

Explanation: Relative dating is a method which is used to determine the geological events that has taken place in the past. It does not give the exact age but can depict about the time when the organisms or the object occurred in the geological time scale. It is very useful on the sedimentary type of rocks.

It helps in describing the stratigraphy of a particular area. And this sedimentary rocks can trap fossils in it that are helpful in determining the past events.

Dmitri Mendeleev organized elements by atomic mass and recurring properties, leaving gaps for undiscovered elements whose properties he predicted accurately.

Dmitri Mendeleev, a chemistry professor, developed the precursor to today's periodic table in 1869. His key breakthrough was arranging the elements not just by their atomic masses but also by the repeating patterns in their properties.

This innovative approach allowed him to leave gaps in the table, predicting that these gaps would later be filled with newly discovered elements.

Mendeleev predicted the properties of these yet-to-be-discovered elements based on the patterns observed in known elements, which included properties such as masses, boiling points, and densities.

When elements like gallium, scandium, and germanium were discovered with properties very close to his predictions, it validated the significance of his periodic table.

Answer:

1500 m/s  

Step-by-step explanation:

The formula for the period T of a wave is

  T = 1/f      Invert each side

(1) f = 1/T

The formula relating frequency f and wavelength λ is

(2) fλ = v     Substitute (1) into (2)

     v = λ/T

Data:

λ = 9 m; T = 0.006 s

Calculations:

v = 9/0.006

v = 1500 m/s

When the sun, moon, and Earth are in alignment (at the time of the new or full moon), the solar tide has an additive effect on the lunar tide, creating extra-high high tides, and very low, low tides—both commonly called spring tide

High tides occur during spring tides when the Sun, Earth, and Moon are aligned, either during new or full moon phases. Low tides occur during neap tides when the Sun and Moon are at right angles with respect to the Earth, typically during the moon's first and third quarters.

Tides are mostly affected by the gravitational pull of the Moon and the Sun on Earth's oceans. High tides, known as spring tides, occur when the Sun, Earth, and Moon are in a straight line. This alignment can happen during the new moon or full moon phases.

Conversely, low tides, referred to as neap tides, occur when the gravitational forces of the Sun and the Moon are perpendicular to each other, which takes place during the first and third quarters of the Moon's phases.

During spring tides, the gravitational forces of the Sun and the Moon combine to create higher-than-average high tides and lower-than-average low tides. During neap tides, the Sun and the Moon's gravitational forces offset each other, resulting in tides that are not as extreme. Therefore, high tides are strongest when the Sun and the Moon are aligned, while low tides are weakest when the Sun is at 90° to the Earth-Moon alignment.

Final answer:

The solution in question is a gaseous solution, and the application of Henry's Law is used to determine the changes in solubility of gases in water based on pressure changes.

Explanation:

The student determined that 8.2 milligrams of oxygen is dissolved in a 1000 gram sample of water at 15 degrees Celsius and 1 atm, which is an example of a gaseous solution. In the context of the given homework questions, this pertains to the application of Henry's Law which describes the solubility of a gas in a liquid at a given temperature is directly proportional to the partial pressure of the gas above the liquid. To determine the solubility under different conditions, you start by using the given solubility at known conditions and calculate the Henry's law constant. Then you can use this constant to find the new solubility when the pressure changes.

Henry's Law is used to determine the changed solubility when the pressure of the gaseous solute is increased from 20.26 kPa (152 torr) to 101.3 kPa (760 torr). This results in a new solubility of 7.25 × 10⁻³ g in 100.0 mL, or 0.0725 g/L. For the Application of Henry's Law and Solution examples at 20 °C, the concentration of dissolved oxygen in water is determined based on its partial pressure changes using the established Henry's law constant.

The most damage from a hurricane typically occurs when it makes landfall.

When a hurricane nears land, several factors contribute to the potential damage it can cause:

Wind Speed: As a hurricane moves onto land, its sustained winds can cause structural damage to buildings, infrastructure, and vegetation. The wind speed at landfall is a crucial factor in determining the extent of the damage.

Storm Surge: Hurricanes generate a significant storm surge, which is the abnormal rise in seawater levels along the coast. This surge, combined with the normal tides, can inundate coastal areas, causing flooding and erosion.

Rainfall: Hurricanes produce heavy rainfall, leading to widespread flooding, particularly in low-lying areas and regions with inadequate drainage systems.

Tornadoes: Hurricanes can spawn tornadoes, which can cause localized destruction within the storm's path.

To estimate the potential damage caused by a hurricane, meteorologists and disaster management agencies consider these factors along with the hurricane's intensity, forward speed, and the population density of the affected areas.

Answer:

Q1. D) A single replacement reaction takes place because sodium is more reactive than hydrogen.

Explanation: [tex]2Na+2H_2O\rightarrow 2NaOH+H_2[/tex] Sodium metal reacts with water to givesodium hydroxide and hydrogen gas. A single replacement reaction takes place because sodium is more reactive than hydrogen.  

Sodium easily lose electrons than hydrogen and get oxidized to [tex]Na^+[/tex] and [tex]H^+[/tex] get reduced to give [tex]H_2[/tex] .

Q2. B) It is a single replacement reaction, and the cations in the two ionic compounds are different.

Explanation: [tex]3Na+AlCl_3\rightarrow 3NaCl+Al[/tex] where Sodium is a metal and [tex]AlCl_3[/tex] is an ionic compound. Na being more reactive than Al, displaces it from its salt solution.

Q3. D) [tex]Zn+H_2SO_4\rightarrow ZnSO_4+H_2[/tex]

Explanation: A single replacement reaction is one in which a more reactive element displaces a less reactive element from its salt solution.Thus zinc can easily lose electrons as compared to hydrogen and result in the formation of zinc sulfate and hydrogen.

Q4. False

[tex]Zn+CaCl_2\rightarrow[/tex]no reaction

Explanation: As zinc lies lower in reactivity series, it is less reactive than calcium. It will not be able to displace calcium from its salt and hence no reaction occur. Thus the given statement is false.

Q5. False

Explanation: A double displacement reaction is one in which exchange of ions take place.  Thus an element replaces another element and not same element.

A single replacement reaction is one in which a more reactive element displaces a less reactive element from its salt solution. Thus one element should be different from another element.

Q6. A)[tex]Na_3PO_4+3KOH\rightarrow  3NaOH+K_3PO_4[/tex], because K retains the same charge throughout the reaction

Explanation: A balanced chemical reaction is one in which the number of atoms on both sides of a chemical equation are same. Also K has an oxidation state or charge of +1 in [tex]KOH[/tex] as well as [tex]K_3PO_4[/tex]

Answer:

Q1: A single replacement reaction takes place because sodium is more reactive than hydrogen.

Explanation:

I take that the insects remain constant no matter what happens to the frogs (which the frogs eat presumably). So a constant food supply for the frogs is not the problem.

The line for the alligators increases over time. It their numbers increase, the frogs are in trouble. The alligators will pursue lunch with determined single mindedness and there are more of them around.

So the frogs should decrease. Their natural enemy is the alligator and alligators won't go after insects. It's not worth their time.

A is the only answer you can choose.

option a

mg atomic number is 12

the electronic configuration is 2, 8, 2

Oxygen atomic number is 8

the electronic configuration is 2,7

the magnesium will try to give away 2 electron to get to the form of noble gas configuration, hence oxygen needs one more to get to noble gas hence it will take two elements of oxygen to form MgO.