BRAINIEST AND MAX POINTS

The diagram below shows four processes, A, B, C, and D, by which carbon circulates between the atmosphere, plants, and animals.

Which processes represent respiration?

Process A and Process C
Process B and Process D
Process A and Process D
Process B and Process C

Answer:

=154.8 J

Explanation:

Change in enthalpy = MC∅ where M is the mass of the substance, C is the specific heat capacity and ∅ is the change in temperature.

Change in temperature = 100.0°C-20.0°C=80°C

ΔH=MC∅

The specific heat capacity of gold= 0.129 J/g°C

ΔH= 15.0g×0.129J/g°C×80°C

=154.8 J

To raise the temperature of a 15.0 gram sample of gold from 20.0°C to 100.0°C, approximately 154.8 joules of heat energy is required, using the formula q = mcΔT where c is the specific heat capacity of gold.

To calculate the heat needed to raise the temperature of gold, you can use the formula:

Q = mcΔT

Where Q is the heat, m is the mass of the gold, c is the specific heat capacity of gold, and ΔT is the change in temperature.

Calculate the change in temperature: ΔT = 100.0°C - 20.0°C = 80.0°C

Look up the specific heat capacity of gold, which is 0.129 J/g°C

Substitute the values into the formula: Q = 15.0g × 0.129 J/g°C × 80.0°C = 154.8 J

Answer:

decrease

Explanation:

I assume you mean pH, the pH will decrease as there are more H+ ions inside the water

Answer:

dissolve i believe its been two years since i was in the class.

Explanation:

Hello There!

A chemical reaction is when one or more molecules combine and rearrange to create one or more molecules or substances.

A chemical reaction is when a reaction occurs that changes the make-up (basically what makes something that thing. For example you have chemical make-up that makes you you. If that make up changed then you wouldn't be you anymore) making what ever was reacted into a NEW product

For example digestion is a chemical reaction. Let's say that you eat a carrot. When digestion (the chemical reaction) is complete the carrot is no longer how it was when your first put it in your mouth. It has been broken down and the acid in your belly changed the chemical make up so that your body can use the carrot for energy

Now let's say that you shred a piece of paper. This is NOT a chemical reaction, because the shredded paper is still the paper it was before it was shredded

Hope this helped!

~Just a girl in love with Shawn Mendes

Final answer:

The equation exemplifies a combustion reaction, where an alcohol reacts with oxygen to produce carbon dioxide and water, commonly releasing heat and light.

Explanation:

The equation provided (2C₃H₅OH + 9O₂ ⇒ 6CO₂ + 8H₂O) is an example of a combustion reaction. In such a reaction, an organic compound (in this case, an alcohol) reacts with oxygen gas to produce carbon dioxide and water as products. Combustion reactions are commonly known for releasing energy in the form of heat and light, which is why they are often associated with burning.

In the combustion reaction given, C₃H₅OH (an alcohol) combusts in the presence of oxygen (O₂) to form carbon dioxide (CO₂) and water (H₂O). This type of reaction is easy to recognize because it typically involves a hydrocarbon (or another organic compound) and oxygen as reactants.

Examples of other types of reactions include:

Answer:

use a calculator please

Answer:

250,000

Explanation:

Answer:

[tex]\boxed{\text{10 \%}}[/tex]

Explanation:

The formula for efficiency is  

[tex]\begin{array}{rcl}\text{Efficiency} & = & \dfrac{\text{useful energy out}}{\text{energy in}} \times 100 \,\% \\\\\eta & = & \dfrac{w_{\text{out}}}{w_{\text{in}} } \times 100 \,\%\\\end{array}[/tex]

Data:

Useful energy =  3 J

Energy input  = 30 J

Calculation:

[tex]\begin{array}{rcl}\eta & = & \dfrac{\text{3 J}}{\text{30 J}} \times 100 \,\%\\\\\eta & = & 10 \, \%\\\end{array}\\\text{ The efficiency is }\boxed{\textbf{10 \%}}[/tex]

The light bulb's efficiency is calculated as 10%, which is the ratio of the useful light energy output (3 joules) to the total energy input (30 joules) per second.

To calculate the efficiency of a light bulb, you need to compare the useful energy output to the total energy input. In this case, the bulb takes in 30 joules of energy per second and transfers 3 joules as useful light energy. The efficiency can be calculated using the formula:

Efficiency (%) = (Useful Energy Output / Total Energy Input) × 100

Plugging the given values into the formula, we get:

Efficiency (%) = (3 J / 30 J) × 100 = 10%

Therefore, the light bulb has an efficiency of 10%.

Answer:The correct answer is C8H18.

Explanation:

Answer:

C₈H₁₈

Explanation:

Octane is an alkane which which is combustible in air.

The combustion of octane C₈H₁₈ in sufficient supply of oxygen produces carbon (IV) Oxide and water only.

Sufficient supply of oxygen ensures there is complete combustion of octane.

2C₈H₁₈ ₍l₎ + 25O₂₍g₎ → 16CO₂₍g₎ + 18H₂O₍l₎

Answer:

Explanation:

Rainwater harvesting is the accumulation and storage of rainwater for reuse on-site, rather than allowing it to run off. Rainwater can be collected from rivers or roofs, and in many places, the water collected is redirected to a deep pit (well, shaft, or borehole), a reservoir with percolation, or collected from dew or fog with nets or other tools. Its uses include water for gardens, livestock,[1] irrigation, domestic use with proper treatment, indoor heating for houses, etc. The harvested water can also be used as drinking water, longer-term storage, and for other purposes such as groundwater recharge.

Rainwater harvesting is one of the simplest and oldest methods of self-supply of water for households usually financed by the user.[2]

Answer:

Rainwater harvesting is discussed below.

Explanation:

Answer:

Tetraoxosulphate vi acid (H2SO4)

Explanation:

Becauses it ionizes completely

Answer:

carborane acid

Explanation:

Answer:

1125mL

Explanation:

this can be done using general gas law

Answer:

The absolute temperature  of the gas will be affected by a fourfold increase.

The pressure must be applied at 450 K should be 1,125 torr.

Explanation:

Charles's Law consists in the relationship between the volume and temperature of a certain amount of ideal gas, which is maintained at a constant pressure, by means of a constant of proportionality that is applied directly. For a given sum of gas at a constant pressure, as the temperature increases, the volume of the gas increases and when the temperature decreases, the volume of the gas decreases because the temperature is directly related to the energy of the movement of the gas molecules .

In summary, Charles's law is a law that says that when the amount of gas and pressure remain constant, the ratio between volume and temperature will always have the same value:

[tex]\frac{V}{T} =k (constant)[/tex]

If you double the volume of a gas sample and  then doubled the volume again, then the volume was increased four times. To comply with Charles's Law and maintain the relationship between volume and constant temperature, the temperature must increase four times, in the same way as volume.

So the absolute temperature  of the gas will be affected by a fourfold increase.

Gay-Lussac's law can be expressed mathematically as follows:

[tex]\frac{P}{T} =k[/tex]

Where P = pressure, T = temperature, K = Constant

This law indicates that the ratio between pressure and temperature is constant.

This law indicates that, as long as the volume of the container containing the gas is constant, as the temperature increases, the gas molecules move faster. Then the number of shocks against the walls increases, that is, the pressure increases. That is, the gas pressure is directly proportional to its temperature.

In short, when there is a constant volume, as the temperature increases, the gas pressure increases. And when the temperature decreases, gas pressure decreases.

When studying two different states of a gas, you have a gas that is at a pressure P1 and at a temperature T1 at the beginning of the experiment. When the temperature varies to a new T2 value, then the pressure will change to P2. This is true:

[tex]\frac{P1}{T1} =\frac{P2}{T2}[/tex]

So in this case, as the volume is constant, Gay-Lussac's law can be applied as follows:

[tex]\frac{750 torr}{300 K} =\frac{P2}{450 K}[/tex]

Then

[tex]P2=\frac{750 torr}{300 K} *450 K\\[/tex]

P2=1,125 torr

The pressure must be applied at 450 K should be 1,125 torr.

Answer:

It's B.

Explanation:

Hope my answer has helped you!

Answer:

B the attraction of metal ions to mobile electrons

Explanation:

Metal bonding occurs when metals are combined with each other. Metal atoms need to give up electrons to reach the configuration of a noble gas. In this case, the metals lose the valence electrons and an electron cloud (also called electron sea) is formed between the positive nuclei

Metals tend to lose the electrons of the last level forming positive ions. When ions are grouped neatly forming a network that is surrounded by the cloud of ceded electrons and a metallic bond is formed

Therefore the correct answer is the B the attraction of metal ions to mobile electrons

The teacher bought 20 cheaper calculators at $2.95 each after setting up and solving an algebraic equation that includes the total cost spent and the price of 40 more expensive calculators.

First, let's define the variables: Let x be the number of cheaper calculators that the teacher bought.

The problem states that the teacher bought 40 calculators at $8.20 each, so this cost is $8.20 times 40, and the other calculators cost $2.95 each, so this is $2.95 times x. The total cost is given to be $387.

We can set up the equation as follows:

$328 + $2.95x = $387

$2.95x = $387 - $328

$2.95x = $59

[tex]x = \frac{\$59}{\$2.95}[/tex]

x = 20

Therefore, the teacher bought 20 of the cheaper calculators.

Answer:

Dynamic equilibrium is a state in which reactant is converted into products at the same rate. At the beginning of a reaction, the reactants are converted to products and reaction goes into forwarding direction.

But in reversible reaction products start changing into reactants and reaction goes in the reverse direction until an equilibrium is reached. The state where the rates of all the reactants and products become equal and no more changes take place except the concentration is called dynamic equilibrium.

All the changes in dynamic equilibrium cancel out each other and the system seems to be at equilibrium.

Answer:

all the changes to a system cancel out

Explanation:

A P E X

Answer:

8.16%

Explanation:

We are to calculate the mass percent of hydrogen in Methyl Acetate.

We know that the formula of Methyl Acetate is [tex]C_3H_6O_2[/tex] so firstly we will find its molecular mass.

Molecular mass of  ([tex]C_3H_6O_2[/tex]) = [tex](12.01 \times 3)+(1.0 \times 6)+(15.9 \times 2)[/tex] = 74.08 g

Mass of Hyrdogen in ([tex]C_3H_6O_2[/tex]) = [tex]1.00784 \times 6[/tex] = 6.05 g

Mass percent of Hydrogen in Methyl Acetate = [tex]\frac{6.05}{74.08} \times 100[/tex] = 8.16%

Answer:

b. s,p,d

Explanation:

The type of orbitals found in the principal energy level n=3 is s, p and d orbitals.

Principal quantum number(n) denotes the energy level in which an orbital is located.

The principal quantum numbers takes values from n = 1, 2,3,4............

For example, the orbitals found in the principal quantum number with a value of 1 is s.

For n = 2, we have s and p

For n = 3, it is given as s, p and d

For n = 4, we have s, p, d and f

Cutting of Nails is a physical change since no new substance is formed.

Proper hand hygiene involves careful cleaning and trimming of the nails, which carry dirt and germs and can contribute to the spread of some infections such as helminths. The nails should be short and the underside should be cleaned frequently with soap and water.

For most people, if you don't trim your nails, your nails will be longer at first. “If you don't trim your nails, your nails will continue to grow,” he says. James Christina, Executive Director and CEO of the American Podiatric Medical Association. "It's like the hair on your head."

Learn more about physical change here: https://brainly.com/question/17609067

#SPJ2

Answer:The appearance of lines in an emission spectrum is caused by the fact that light is released as an electron moves to a lower energy state. When the atoms absorb energy they get excited and reach a higher level of energy. Then, when those atoms that are unstable release energy they pass to a lower level and emit light.

The appearance of lines in an emission spectrum​ is caused by the gas cloud on its own, without a light source behind it.

Hence, the appearance of lines in an emission spectrum​ is caused by the gas cloud on its own, without a light source behind it.

To learn more about the emission spectrum, refer to: https://brainly.com/question/2726279

#SPJ2

Answer:

The correct answer is D: 16.4 g

Explanation:

Look at the balanced equation of NaBr, It has 1:1 between Na and Br.

NaBr ---> Na+ and Br-

If the solution has 0.245 concentration of bromide ions then the solution has 0.245 concentration of sodium ions as well. Which means both have equal concentration. So the molarity of solution is 0.245 M.

Convert volume in dm3.

650ml = 650 cm3  

650cm3/ 1000cm3 x 1dm3 = 0.65 dm3

Mass of a solute (g) = Molarity x Molar mass of solute x volume in dm3

                               = 0.245 M X 102.89 g/mol x 0.65 dm3

                             = 16.38 = 16.4 g

Answer:

The correct answer is D) 16.4.

The mass of sodium bromide in solution is 16.4 g

Further Explanation:

Molarity may be defined as the concentration of a solution in moles per liter. It is calculated by dividing the number of moles of a solution, n by its volume in liters, V. That is; Molarity = n/V

Therefore; when given the molarity of a solution and the volume of the solution then we can get the number of moles, by multiplying the molarity by volume; n = MV.

Additionally, the number of moles of a compound or an element can also be calculated by dividing the mass of the compound by its relative molecular mass.

In this question, we are given;

Molarity of a bromide ion = 0.245 M

But the dissociation of sodium bromide is;

NaBr(aq) → Na+(aq) + Br-(aq)

Therefore, the molarity of NaBr is 0.245 M since the mole ratio of NaBr : Br- is 1: 1.

Hence; Number of moles of NaBr = Molarity × volume

                                                        = 0.245 M × 0.650 L

                                                        = 0.15925 moles

But; number of moles = mass/ molecular mass

Molecular mass of NaBr is 102.894 g/mol

Therefore;

Mass of NaBr = Number of moles × molecular mass

                      = 0.15925 × 102.894 g/mol

                      = 16.385 g

                      ≈ 16.4 g

Thus, the mass of sodium bromide in solution is 16.4 g

Grade: Middle  School

Subject: Chemistry

Chapter: Mole and stoichiometry equations

Keywords: Molarity, moles, sodium bromide, molecular mass and volume.

Answer:

nonpolar, trigonal planar and nonpolar

Explanation:

The borane molecule BH3 has nonpolar bonds due to the similar electronegativities of boron and hydrogen, a trigonal planar molecular shape, and is nonpolar overall due to its symmetrical structure.

Complete the paragraph to describe the characteristics of a borane molecule (BH3). The bond polarities in BH3 are nonpolar, the molecular shape is trigonal planar, and, due to its symmetry, the molecule is nonpolar.

The borane molecule, BH3, consists of a boron atom undergoing sp² hybridization. The boron atom is involved in three bonds with hydrogen atoms, resulting in a trigonal planar structure. This configuration uses three sp² hybrid orbitals where each of the boron's valence electrons pairs with a hydrogen electron, forming covalent bonds. Despite the polar bond character between boron and hydrogen, due to similar electronegativities of 2.04 for boron and 2.20 for hydrogen, the symmetry of the molecule ensures those individual dipoles cancel out, rendering the molecule nonpolar on the whole.

https://brainly.com/question/30076432

#SPJ6

Answer:

In materials of molecular structure, the nature of intermolecular and intramolecular bonds has a decisive influence on their characteristics and properties. Characteristics such as melting and boiling points, mechanical strength and hardness depend on the type of such bonds.

Answer:

0.0116 mol.

Explanation:

It is known that at STP: 1 mol of any gas occupies 22.4 L.

Using cross multiplication:

1 mol of NH₃ occupies → 22.4 L.

??? mol of NH₃ occupies → (520 mL) 0.52 L.

∴ The no. of moles of (520 mL) NH₃ produced = (1 mol)(0.52 L)/(22.4 L) = 0.0232 mol.

3H₂ + N₂ → 2NH₃.

3 mol of H₂ react with 1 mol of N₂ to produce 2 mol of NH₃.

Using cross multiplication:

1 mol of N₂ produce → 2 mol of NH₃, from stichiometry.

??? mol of N₂ produce → 0.0232 mol of NH₃.

∴ The no. of moles of N₂ needed = (1 mol)(0.0232 mol)/(2 mol) = 0.0116 mol.

Approximately 0.0116 moles of nitrogen would react with excess hydrogen to produce 520 mL of ammonia. This calculation is based on the balanced equation N₂ + 3 H₂ → 2 NH₃ and the molar volume of a gas at STP. It ensures that the stoichiometric ratio is maintained.

First, let's recall the balanced chemical equation for the synthesis of ammonia:

N₂ + 3 H₂ → 2 NH₃

According to the balanced equation, 1 mole of nitrogen reacts with 3 moles of hydrogen to produce 2 moles of ammonia. Given that volume and moles correlate under ideal conditions (at STP - Standard Temperature and Pressure), 1 mole of gas occupies 22.4 liters (or 22,400 mL). To find the moles of ammonia produced, we can use the given volume:

Number of moles of ammonia (NH₃) = Volume of NH₃ / Molar volume at STP

= 520 mL / 22400 mL/mol

= 0.0232 moles of NH₃

From the stoichiometry of the reaction, 2 moles of NH₃ are produced from 3 moles of H₂ and 1 mole of N₂. Therefore, we need to find out how many moles of nitrogen (N₂) are required to produce 0.0232 moles of NH₃. Using the mole ratio from the balanced equation:

(1 mole of N₂) / (2 moles of NH₃) = x moles of N₂ / 0.0232 moles of NH₃

x = 0.0232 / 2

= 0.0116 moles of N₂

Thus, approximately 0.0116 moles of nitrogen would react with excess hydrogen to produce 520 mL of ammonia.

Answer:

32.5kg

Explanation:

if 1kg = 1000g,

then xkg=32500g

to convert, divide by 1000 32500/1000=32.5kg

C. alpha = nucleus of a helium atom

beta = electron

gamma = photon

Answer : The correct option is, (C) alpha = nucleus of a helium atom, beta = electron,  gamma = photon

Explanation :

Alpha particle : It is also known as alpha radiation or alpha ray that consists of 2 protons and 2 neutrons that are bound together into a particle that is identical to the helium nucleus. It is produced in the process of alpha decay.

Beta particle : It is also known as beta radiation or beta ray. During the beta decay process, a high energy and speed electron or positron are emitted by the radioactive decay of atomic nucleus.

Gamma particle : It is also a gamma radiation or gamma ray that is arising from the radioactive decay of atomic nuclei. It has shortest wavelength waves and imparts high photon energy can pass through most forms of matters because they have no mass.

Hence, the correct option is, (C) alpha = nucleus of a helium atom, beta = electron,  gamma = photon

Answer:

by equal number of protons and electrons it balances it out

Due to interaction of proton particle and electron particle, neutrality in atom is achieved.

It is a common known statement that matter is composed of atom, and atom is composed of particles called as electron, neutron, and proton. The atoms are considered as charged particles due to the presence of charges on its composition molecules.

The electrons are negative charged particles whereas the protons are positively charged particles. The number of protons and electron in an atom remains equal. Due to this condition, all the protons react with the entire electron leading to a condition called neutrality.  

Answer:

A very large amount of energy is produced from a series of chemical reactions.

Explanation:

Nuclear fission is the process of splitting apart nuclei (usually large nuclei). When large nuclei, such as uranium-235, fissions, energy is released. So much energy is released that there is a measurable decrease in mass, from the mass-energy equivalence. This means that some of the mass is converted to energy.

Answer:

2nd option

Explanation:

Nuclear fission is the process of splitting apart nuclei (usually large nuclei). When large nuclei, such as uranium-235, fissions, energy is released. So much energy is released that there is a measurable decrease in mass, from the mass-energy equivalence. This means that some of the mass is converted to energy.

To find the current through the nightlight bulb, you can use Ohm's Law, which states that current (I) is equal to voltage (V) divided by resistance (R). The current through the bulb is approximately 0.02917 Amperes, or 29.17 milliamperes (mA).

To find the current through the nightlight bulb, you can use Ohm's Law, which states that current (I) is equal to voltage (V) divided by resistance (R). In this case, the resistance is equal to the power (P) divided by the voltage (V). So, the current (I) can be calculated as follows:

I = P / V

Substituting the values given, we have:

I = 3.5 watts / 120.0 volts

Calculating this equation, we find that the current through the bulb is approximately 0.02917 Amperes, or 29.17 milliamperes (mA).

https://brainly.com/question/28876459

#SPJ2

Answer:

37.67 g.

Explanation:

CaH₂(s) + 2H₂O(l) → Ca(OH)₂(aq) + 2H₂(g).

It is clear that 1 mol of CaH₂(s) reacts with 2 mol of H₂O(l) to produce 1 mol of Ca(OH)₂(aq) and 2 mol of H₂(g).

We can use the general law of ideal gas: PV = nRT.

where, P is the pressure of the gas in atm (P = 0.995 atm).

V is the volume of the gas in L (V = 45.0 L).

n is the no. of moles of the gas in mol (n = ??? mol).

R is the general gas constant (R = 0.0821 L.atm/mol.K).

T is the temperature of the gas in K (T = 32.0° + 273 = 305.0 K).

∴ n = PV/RT = (0.0995 atm)(45.0 L)/(0.0821 L.atm/mol.K)(305.0 K) = 1.79 mol.

1 mol of CaH₂(s) produces → 2 mol of H₂(g), from stichiometry.

??? mol of CaH₂(s) produces → 1.79 mol of H₂(g).

∴ no. of moles of CaH₂(s) needed = (1 mol)(1.79 mol)/(2 mol) = 0.895 mol.

∴ mass of CaH₂ = (no. of moles)(molar mass of CaH₂) = (0.895 mol)(42.094 g/mol) = 37.67 g.

Approximately 37.5 grams of Calcium Hydride (CaH2) are needed to produce 45.0 L of Hydrogen gas at a pressure of 0.995 atm and a temperature of 32 °C.

The subject of this question is the calculation of the mass of Calcium Hydride (CaH2) required to generate a specific volume of Hydrogen gas (H2) under certain conditions. According to the ideal gas law, PV = nRT, we can find the number of moles of hydrogen (n) needed. Given P=0.995 atm, V=45.0 L, R=0.0821 (the ideal gas constant in terms of atm, L, mol, K), and T = 32°C = 305.15 K, n = (P*V)/(R*T) which gives approximately 1.78 moles of hydrogen.

From the balanced chemical equation, we know that 1 mole of CaH2 produces 2 moles of H2. Therefore, we need 0.89 moles of CaH2 to produce 1.78 moles of H2. Knowing that the molar mass of CaH2 is approximately 42.1 g/mole, the mass needed can be calculated as: mass = moles * molar mass = 0.89 moles * 42.1 g/mole = approx. 37.5 g. Hence, approx. 37.5 grams of CaH2 are needed to generate 45.0 L of H2 at a pressure of 0.995 atm and a temperature of 32 °C.

https://brainly.com/question/32229244

#SPJ3

Answer:

=1.666 liters

Explanation:

1 mole of a has at standard temperature and pressure occupies a volume of 22.4 liters.

0.5 moles of nitrogen occupy a volume of (0.5 moles×22.4 dm³/mol)/ 1

=11.2 liters.

Standard pressure= 1 atmosphere (Atm)

Standard temperature = 273.15 Kelvin

According to Combined gas equation, P₁V₁/T₁=P₂V₂/T₂

Let us take the conditions under standard conditions as the reference, with the subscript 1 and the conditions under the 5L container to be scenario 2 with subscript 2.

Therefore P₂ =P₁V₁T₂/T₁V₂

Substituting for the values we get:

P₂= (1 atm× 11.2L ×203K)/ (273K×5L)

=1.666 atm

Answer:

a thing that is composed of two or more separate elements; a mixture.

Explanation: