I don’t get this at allll

Answer:3

Explanation: counting from left to right there is 3 sig figs.

40.5%

Explanation:

Ca×1 = 40

C×4 = 48

H×6 = 6

O×4 = 64

64÷158×100% = 40.5%

According to given Information:

The energy change of the reaction is -20kJ  is true statement, This is exothermic reaction.

Exothermic meaning that the products of the reaction have lower energy than the reactants.

The negative value of the energy change (-20kJ) indicates that energy is released during the reaction.

Energy change refers to the difference in energy between the products and reactants of a chemical reaction. If the energy change is positive, it means that energy is absorbed by the reaction and the reaction is endothermic.

If the energy change is negative, it means the energy is released by the reaction and the reaction is exothermic. The magnitude of the energy change provides information about the amount of energy that is released or absorbed during the reaction

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Answer:

Explanation:

The pollutants can cause algae to grow quickly. These 'blooms' of algae may produce toxins that harm other life in the river. When the algae die and decay, this uses up much of the oxygen in the stream. Without enough oxygen in the water, invertebrates and fish will suffocate .

Answer:

D, all of the above.

Explanation:

Pollutants have many bad effects on living beings around. All of stated in the answer options makes sense.

A chemical reaction is known by;

2. Heat is released

3. A gas is given off

A change in color may indicate that a chemical reaction has occurred. For example, when iron is exposed to air and moisture, it rusts and turns from silver to reddish-brown.

If a gas is produced during a reaction, it can indicate that a chemical reaction has occurred. For example, when baking soda is mixed with vinegar, carbon dioxide gas is produced, which causes bubbles to form.

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The Brnsted-Lowry acid-base hypothesis states that when a molecule gives a proton (H+ ion) to another molecule, it behaves as an acid. As a result, the right response is (3) donates an H+.

The Arrhenius theory states that acid is a chemical that causes water to create hydrogen ions. Base is a chemical that causes water to form hydroxide ions.

A neutralisation reaction takes place during the acid-base titration. Here, the concentration of a particular base or acid is ascertained by neutralisation against an acid or base of known concentration. This kind of titration begins with a drop of an indicator, which changes colour to show the endpoint.

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Well, us human being rely on [tex]o_{2}[/tex] (oxygen). We human beings breathe this in every day because we need it to survive. This is a good example because it explains how humans don't see [tex]o_{2}[/tex] but use it every day.

Answer:

1 mole = 6.022×10^23 atoms. 1 water molecule = 2 Hydrogen atoms + 1 oxygen atom. So, 1 mole H2O = 1.2044×10^24 hydrogen atoms. Therefore 2 mole H2O will have 2.4088×10^24 hydrogen atoms.

Explanation:

When a protonated epoxide is attacked by water, the nucleophile attacks from the "top" or "front" of the epoxide ring in an "S_N2" substitution nucleophilic bimolecular process.

A protonated epoxide is a molecule that contains an epoxide ring (a three-membered ring consisting of two carbon atoms and one oxygen atom) that has been protonated, or had a hydrogen ion (H+) added to it.

The protonation of an epoxide ring can occur in the presence of an acidic medium, such as a strong acid like sulfuric acid (H2SO4) or hydrochloric acid (HCl).

In acidic conditions, the lone pair of electrons on the oxygen atom of the epoxide ring can interact with the positively charged hydrogen ion, resulting in the formation of a protonated epoxide.

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The infusion will be finished in 114.286 hours.

We need to infuse 100 mg of Drug Z. Since the IV solution contains 0.0175% of Drug Z, we can calculate the amount of IV solution needed for the infusion.

To do this, we need to use the following formula:

Amount of IV solution = [tex]\frac{(Amount of Drug Z * 100) }{ Concentration of Drug Z}[/tex]

Amount of IV solution = [tex]\frac{(100 mg * 100) }{0.0175 \% }[/tex]

Amount of IV solution = 5,714.286 ml

To calculate how long it will take to complete the infusion, we need to use the following formula:

Time to complete infusion =[tex]\frac{Amount of IV solution }{ Rate of infusion }[/tex]

Time to complete infusion =[tex]\frac{ 5,714.286 ml }{ 50 ml/hr }[/tex]

Time to complete infusion = 114.286 hr

Therefore, it will take 114.286 hours to complete the infusion.

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Answer:I think your talking about the chromatin

Explanation: There dark

A liquid's viscosity is a measurement of its flow resistance. A liquid's resistance to flow increases with its viscosity. Due to its high density and high molecular weight, honey is regarded as an extremely viscous liquid. Honey has a high viscosity since it is mostly composed of glucose and fructose.

Conversely, paint and dish soap is less viscous because they are not as heavy or dense as honey. The mixture of pigments, solvents, and additives used to make paint gives it a variety of viscosities. Due to its low molecular weight and the presence of surfactants, dish soap often has a low-viscosity liquid.

On the basis of this data, it can be predicted that dish soap will have the lowest viscosity, followed by paint, and then honey. This is true because paint and dish soap have lower molecular weights and are lighter and less dense than honey, which is a viscous, dense liquid with a high molecular weight.

Temperature and pressure have an impact on a liquid's viscosity as well, so it is important to regulate these variables when testing this idea experimentally to assure accuracy. As different brands and formulas might differ in their composition and viscosity, it is also crucial to keep in mind that the type and quality of the paint and dish soap under test may have an impact on the findings of the viscosity test.

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Answer: 2.31 mole H2O

Explanation: blance the equation first

4 NH3 +   5O2   --> 4 NO + 6 H20

1.54 moles NH3 x ( 6 mole H20/ 4 moles NH3) X (18 g H20/1mole H20)

2.31 mole H20

The IUPAC name of the compound is 3-Ethyl-2,2-dimethylhexane.

IUPAC naming is a systematic method of naming chemical compounds according to a set of rules established by the International Union of Pure and Applied Chemistry. It ensures that each compound has a unique and unambiguous name based on its molecular structure.

From the image:

Thus, the IUPAC name of the compound is 3-Ethyl-2,2-dimethylhexane.

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The mole fraction of HCl in the given solution is 0.051.

To calculate the mole fraction of HCl in the given solution, we need to first find the mass of HCl and water present in the solution.

Let's assume we have 100 g of the solution, so 9.8 g of it is HCl, and 90.2 g is water.

Next, we need to find the moles of HCl present in the solution.

To do this, we divide the mass of HCl by its molar mass.

The molar mass of HCl is 36.46 g/mol (1.01 g/mol for hydrogen + 35.45 g/mol for chlorine).

moles of HCl = 9.8 g / 36.46 g/mol = 0.269 mol

The moles of water can be calculated using its molar mass which is 18.015 g/mol.

moles of water = 90.2 g / 18.015 g/mol = 5.005 mol

The total number of moles in the solution is the sum of the moles of HCl and water.

total moles = 0.269 mol + 5.005 mol = 5.274 mol

The mole fraction of HCl can now be calculated by dividing the moles of HCl by the total number of moles.

mole fraction of HCl = 0.269 mol / 5.274 mol = 0.051

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Answer:

Explanation:

Pressure and volume are indirectly related.

Pressure and temperature are directly related.

so first ? is increase

2nd ? is decrease

Answer:

d

Explanation:

Nitrogen is the limiting reactant.

42 g N2x (1mole N2/28 g N2) X (2 moles NH3/ 1mole N2) X (17 grams NH3/1mole NH3) = 51 g

13 g H2 x (1 mole H2/2 g H2) X (2 moles NH3/3moles H2) X (17 g NH3/1mole NH3) =73.66g

since 51 is smaller than 73.66 and it started with N2 that is why N2 is the limiting reactant)

Acids have a strong tendency to corrode. Acid splashing on our flesh can result in severe burns and skin irritation. Therefore, when managing acids, we should exercise caution.

Although acids and bases are frequently used in a wide range of industrial applications, it's essential to keep in mind that they are hazardous waste and should be handled carefully.

When working with concentrated acids or acid solutions, put on chemical splash goggles, chemical-resistant mittens, and a chemical-resistant apron. In a fume cover, work with concentrated acids. In accordance with your requirements, purchase diluted acid solutions. It is safer and simpler to manage, store, and use diluted solutions.

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The heat capacity of an object is defined as the amount of heat required to raise its temperature by 1 degree Celsius (or 1 Kelvin). It is denoted by the symbol "C" and has units of J/°C (Joules per degree Celsius) or J/K (Joules per Kelvin).

We can use the formula for heat capacity to calculate its value for the object:

where:

Substituting the given values, we get:

Note that the units of temperature must match (either Celsius or Kelvin) in order for the calculation to be correct. Since the given change in temperature is in Celsius, we can use Celsius for the units of heat capacity as well.

Dividing, we get:

Therefore, the heat capacity of the object is 95.8 J/°C. This means that it requires 95.8 Joules of heat to raise the temperature of the object by 1 degree Celsius (or Kelvin).

[tex]\rule{200pt}{5pt}[/tex]

Answer:

To convert 675000 to scientific notation, we need to express it in the form a × 10^n, where a is a number between 1 and 10 (but not 10 itself), and n is an integer.

Starting with 675000, we can divide by 10 repeatedly until we get a number between 1 and 10.

675000 ÷ 10 = 67500 (one division by 10)

67500 ÷ 10 = 6750 (two divisions by 10)

6750 ÷ 10 = 675 (three divisions by 10)

Now we have a number between 1 and 10 (namely, 6.75), and we know that we divided by 10 three times, so the exponent is -3.

Therefore, we can express 675000 in scientific notation as:

6.75 × 10^5

(Note that we could also express it as 6.75 × 10^2 × 10^3, but this is not in standard scientific notation, which requires the coefficient to be between 1 and 10.)

O:C:H ratio is 34.8/16/52.2/12/13/0/1 = 2.17/4.35/13/0 = 1:2/6. Hence, C2H6O is the empirical formula (option D).

Fuel cells may produce heat and energy from hydrogen. Although transportation and utilities are expanding businesses, fertilizer manufacturing and petroleum refining still use hydrogen most frequently today.

According to the 1992 Energy Policy Act, hydrogen qualifies as an alternative fuel. The ability of hydrogen to power fuel cell technology in zero-emission vehicles, the potential for home consumption, and the high efficiency and quick filling time of fuel cells all contribute to the interest in hydrogen as such an alternative transportation fuel.

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There are therefore a total of 14 atoms: 2 Al, 3 C, & 9 O. In other words, 3.5 moles of calcium carbonate will contain 3.5 moles if carbon because each mole of calcium carbonate has one mole of carbon.

Hence, 40.078 divided by 100.086 everything multiplied by 100% represents the mass percentage for calcium in calcium carbonate. This yields a value of almost 40%. Carbon's mass percentage is calculated by taking 12.011 and dividing it by 100.086, then multiplying that result by 100% to get a number of roughly 12 percent.

The subscripts (2 and 3) in this formula indicate how so many atoms will make up one unit of the molecule. There are two aluminium atoms and three oxygen atoms, respectively, denoted by the numbers 2 and 3.

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Answer:

Explanation:

The element with the highest electronegativity is Flourine.  Its value is 4.  Thus it increases across a period.  

Its trend is it increases from left to right and up the groups.  So it will decrease going down the group.  

At 60.0 °C, the air has a volume of 1650.0 mL.

At constant pressure, the volume of a gas is directly proportional to its temperature.This means that when the temperature increases, the volume of the gas also increases.

At 20.0 °C, the volume of the air is 550.0 mL.

Using the formula [tex]V2 = V1 *\frac{ T2}{T1}[/tex], where the initial volume and temperature are V1 and T1, respectively, and the end volume and temperature are V2 and T2, respectively.

we can calculate the volume of the air at 60.0 °C.

[tex]V2 = 550.0 mL * (\frac{60.0 \°C}{20.0 \°C})[/tex]

V2 = 1650.0 mL

Therefore, the volume of the air at 60.0 °C is 1650.0 mL.

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The substance is lithium (Li).

Isotopes are atoms of the same element with variable numbers of neutrons but the same number of protons in their nucleus.

Hence, although having different atomic masses, they have the same atomic number.

The physical characteristics of an element's isotopes can differ from their chemical characteristics because of their varied atomic masses.

Isotopes include, for instance:

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By a redox reaction that involves the transfer of electrons, often through the dissolution of an ionic substance, electrochemical cells produce electricity from the flow of electrons.

In electrochemistry, redox or oxidation-reduction reactions, in which electrons travel from one element to another, can produce electricity. Redox processes involve the transfer of electrons from one substance to another.

Batteries use a very significant class of oxidation and reduction reactions to produce useable electrical energy. Using solutions of respective sulphates, copper and zinc metals can be combined to create a straightforward electrochemical cell.

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A. The balanced chemical equation with phase labels is: BaCl2 (aq) + K2O (aq) → BaO (s) + 2KCl (aq)

B. This is a double displacement or metathesis reaction, as the cations and anions of the reactants switch places to form new compounds.

C. The indicator that a chemical reaction has occurred is the formation of a solid (BaO) and the disappearance of the reactants (BaCl2 and K2O) as they react to form products (BaO and KCl).

A balanced chemical equation is a representation of a chemical reaction using chemical formulas of the reactants and products, and coefficients to indicate the relative numbers of each.

The coefficients are used to balance the equation such that the number of atoms of each element in the reactants is equal to the number of atoms of the same element in the products.

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Answer:

It would be higher

Explanation:

If bromophenol blue was used instead of phenolphthalein in the CH3COOH-NaOH titration, the calculated molarity of acetic acid would be higher. This is because the pH range for bromophenol blue is lower than that of phenolphthalein (approximately 3.0 to 4.6 compared to 8.2 to 10.0). Therefore, the endpoint of the titration (where the indicator changes color) would occur at a lower pH for bromophenol blue, indicating that more NaOH has been added to neutralize the acetic acid. This would result in a higher calculated molarity of acetic acid.

Answer:

D

Explanation: