1 point
A student is classifying a group of unknown solids by whether or not they float or sink in water.

Which property is the student using to classify the solids?

mass

solubility

density

melting point

Answer:

18.015

Explanation:

Using the periodic table of the elements to find atomic weights, we find that hydrogen has an atomic weight of 1, and oxygen's is 16. In order to calculate the molecular weight of one water molecule, we add the contributions from each atom; that is, 2(1) + 1(16) = 18 grams/mole.

Answer:

How do amoeba respire.

Define Diffusion.

The amount, in kJ, of heat needed to completely vaporize 50.0g of water at 100°C is 118.8 kJ.

The heat needed to completely vaporize 50.0g of water at 100°C can be calculated using the following formula:

q = m x Hv

where:

First, we need to convert 50.0g to moles by dividing by the molar mass of water which is approximately 18.015 g/mol3:

moles of water = 50.0 g / 18.015 g/mol moles of water = 2.776 mol

Thus:

q = (2.776 mol) x (40.65 kJ/mol) q = 112.8 kJ

In other words, 112.8 kJ of heat is needed to completely vaporize 50.0g of water at 100°C.

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Answer: Molar mass of \(NH_3\) is 17.03 g

Explanation:

Molar mass is defined as the mass in grams of 1 mole of a substance.

S.I Unit of Molar mass is gram per mole and it is represented as g/mol.

It is found by adding the atomic masses of all the elements present.

Atomic Mass of Nitrogen (N) = 14.007 g

Atomic Mass of Hydrogen (H) = 1.008 g

Molar mass of \(NH_3\) = 1(14.007)+3(1.008) g = 17.03 g

Answer:

B, Gas B.

Explanation:

Answer:

Ca = 40.1 g

Cl = 35.5

40.1 + 35.5×2

40.1 + 71

111.1 g

Answer:

A) the CH3 group

Explanation:

Answer:

Did you get the answer to this?

Explanation:

I need this too.

Answer: The pressure in the container is 1949.5 torr when the volume is 7.20 liters and the temperature is 71.0 °C

Explanation: To solve this problem, we can use the combined gas law, which relates the initial and final conditions of pressure (P), volume (V), and temperature (T) for an ideal gas:

(P1 × V1) / T1 = (P2 × V2) / T2

where P1, V1, and T1 are the initial pressure, volume, and temperature, and P2, V2, and T2 are the final pressure, volume, and temperature.

We can plug in the given values:

P1 = 740.5 torr

V1 = 10.8 L

T1 = 23.0 °C + 273.15 = 296.15 K

V2 = 7.20 L

T2 = 71.0 °C + 273.15 = 344.15 K

(P1 × V1) / T1 = (P2 × V2) / T2

(740.5 torr × 10.8 L) / 296.15 K = (P2 × 7.20 L) / 344.15 K

Solving for P2:

P2 = (740.5 torr × 10.8 L × 344.15 K) / (296.15 K × 7.20 L)

P2 = 1949.5 torr

Therefore, the pressure in the container is 1949.5 torr when the volume is 7.20 liters and the temperature is 71.0 °C.

Knowing the pH of a solution is not enough to determine its molarity, unless additional information about the chemical nature of the solution is provided. In the case of tomato juice, it is a complex mixture of various organic and inorganic compounds, including citric and malic acids, which contribute to its acidity.

The pH of a solution is defined as the negative logarithm (base 10) of the hydrogen ion concentration [H+] in moles per liter (M):

pH = -log[H+]

pH = -log(Ka / [H+])

[H+] = Ka / \(10^(^-^p^H^)\)

However, for a complex mixture like tomato juice, the concentration of hydrogen ions (and hence its molarity) is determined by the concentrations of all the acids present in the solution, which may not be the same for different samples of tomato juice.

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no. of moles in uncut diamond are 13.11 mol and number of Carbon atoms are 78.94 × 10^23.

The mass of a substance is given in this case. We are aware that the diamond is Carbon's allotrope.

weight of diamond before cutting = 787 carats

1 carat. = 0.200 gram

therefore, 787 carats. = 787 × 0.200

= 157.4 gram

To calculate the number of moles equation is

Number of moles =Mass / Molar mass

Molar mass of carbon Is 12g/mol

therefore, no. of moles = 157.4 / 12 = 13.11 mol

We know that 1 mol of any substance contains 6.022×10^23 atoms.

Here we have 13.11 mol of carbon. thus,

No. of Carbon atoms = 13.11 × (6.022×10^23 / 1 mol) = 78.94 × 10^23

Thus, 13.11 mol of diamond contain 78.94 × 10^23 number of Carbon atoms.

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Answer:

Explanation:

The moles of HCl added to this mixture = 0.0375 mol

The chemical equation for this reaction: NaOH + HCl → NaCl + H2O

NaOH is the limiting reagent.

Qsurr = -Qrxn = -4.68 kJ

Enthalpy for the neutralization reaction: -62.72 kJ/mol

Thermochemical equation for the dissociation of sodium hydroxide:

a) NaOH → Na+ + OH-

b) NaOH(s) → Na+(aq) + OH-(aq)

The percent error for the experiment is calculated to be 6.17%.

The sources of experimental error could be variations in the temperature measurements, evaporation of the solutions leading to a lower mass, and heat loss due to inadequate insulation.

In terms of bonds breaking and forming, the breaking of the ionic bond in NaOH and the formation of new bonds between Na+ and Cl- and between H+ and OH- are responsible for the enthalpy change.

Conclusion: The purpose of this experiment was to determine the heat of solution of sodium hydroxide and the heat of neutralization between sodium hydroxide and hydrochloric acid. Based on the experimental results, the enthalpy change for the neutralization reaction was found to be -62.72 kJ/mol.

Enthalpy of neutralization between sodium hydroxide and hydrochloride was calculated to be 19.47 kJ/mol. Compared to the real value of -57.9 kJ/mol, this number is 134.5% off.

The amount of heat generated during the neutralisation reaction that results in the formation of water and salt from one equivalent of an acid and one equivalent of a base is known as the heat of neutralisation of an acid.

1) We must apply the following formula to figure out how many moles of hydrochloride were added to the mixture:

moles = concentration x volume

Substituting the given values, we get:

moles HCl = 0.75 M x 0.0500 L = 0.0375 moles hydrochloride

2) The following is the chemical formula for the reaction of sodium hydroxide with hydrochloric acid:

NaOH(aq) + HCl(aq) → NaCl(aq) + H2O(l)

3) As NaOH has a stoichiometric coefficient of 1 in the balanced chemical equation, 0.0375 moles of hydrochloride are also necessary for the entire reaction.

moles HCl used = 0.75 M x 0.0500 L = 0.0375 moles hydrochloride

4) To calculate Qsurr, we use the formula:

Qsurr = -qsys = -Ccal x ΔT

T = 27°C - 23.5°C = 3.5°C since the calorimeter's temperature rose from 23.5°C to 27°C. If the calorimeter has a heat capacity of 100 J/°C, then:

Qsurr = -Ccal x ΔT = -100 J/°C x 3.5°C = -350 J

To calculate Qrxn, we use the formula: Qrxn = -Qsurr = 350 J

Converting Qrxn to kJ, we get: Qrxn = 0.350 kJ

5) We employ the formula to calculate the enthalpy change for the neutralising process: ΔHrxn = Qrxn / moles hydrochloride

Substituting the calculated values, we get:

ΔHrxn = 0.350 kJ / 0.0375 moles = -9.33 kJ/mol hydrochloride

The exothermic nature of the reaction, which releases heat, is shown by the negative sign.

6) There are two ways to express the thermochemical equation for the dissociation of sodium hydroxide:

sodium hydroxide(s) → Na+(aq) + OH-(aq) ΔH = 44.5 kJ/mol (endothermic)

sodium hydroxide(aq) → Na+(aq) + OH-(aq) ΔH = -44.5 kJ/mol (exothermic)

7) Enthalpy of neutralisation between hydrochloric acid and sodium hydroxide is really -57.9 kJ/mol. We apply the following formula to get the percent error:

% error = |experimental - actual| / actual x 100%

Substituting the values, we get:

% error.

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The electronic configuration is given as a gray circle is labeled 5 P 6 N. It is surrounded by two concentric circles. The inner circle has gray dots at the north and south positions. Option B

Electron configuration is simply described as the even distribution of electrons in an atom's energy levels, orbitals, and sub orbitals.

It also shows the arrangement of electrons within the electron shells of an atom

The sublevels are written as  (s, p, d, f),

Also, the energy levels, also known as electron shells, are denoted by whole numbers (1, 2, 3, etc)

For Helium with only two electrons, we have;

1s²

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Answer:

Any element in group 1 has just one valence electron. Examples include hydrogen (H), lithium (Li), and sodium (Na). Any element in group 18 has eight valence electrons (except for helium, which has a total of just two electrons).

Explanation:

How many valence electrons does each element have?

The Group 1 atoms have 1 valence electron. The Group 2 atoms have 2 valence electrons. The Group 3 atoms have 3 valence electrons. The Group 4 atoms have 4 valence electrons.

I hope it's helpful

Answer:

Explanation:

Avogadro's number, 6.022 * 1023 is the number of things in one mole. The question indicates that there is 1 mole of H2. Thus there are 6.022 * 1023 molecules of H2

relating to, or forming an orbit (such as the orbit of a moon, planet, or spacecraft)

Answer:

Explanation:

Electron orbitals are the three-dimensional areas around the nucleus of an atom where a particular electron resides. Each orbital can hold two electrons. They are also known as atomic orbitals. Atomic orbitals come in different shapes, depending on the number of electrons the atom has.

The precise definition of an orbital, is a mathematical function that describes the location of an electron in an atom, based on probability. “Atomic orbital” generally refers to the region of space where an electron could possibly be present, based on the mathematical function for that orbital.

Answer:

That element is selenium, Se

Answer:

D. 132.17 amu

Explanation:

The formula mass of a compound can be determined from the formula of the compound thus, from the number each elements present. The formula mass of (NH₄)₂SO₄ is 132.17 amu.

What is formula mass?

Formula mass of a compound is the mass calculated from its formula. Each elements has a definite mass called its atomic mass expressed in g/mol or amu.

Mass number of an element is the sum of number of its protons and neutrons. The actual mass of an element is calculated with respect to the mass of 1/12th of Carbon-12 and it is called relative mass.

Here, the atomic mass of N = 14.006 amu

                        mass of H = 1.008 amu.

There are 4 hydrogen thus 4 × 1.008 = 4.008 u.

The mass of two units of  NH₄ is = (14.006 + 4.008) × 2

                                                      = 36.028 u.

Atomic mass of sulfur = 32.6 amu

atomic mass of oxygen = 15.9 amu.

Thus for 4 oxygens = 15.9 × 4 =  63.6 u

The mass of SO₄ unit = 32.06 + 67.6 = 96.2u

Thus the total mass of (NH₄)₂SO₄ = 96.2 + 36.028

                                                        = 132.17 amu

Hence, the formula mass of (NH₄)₂SO₄ is 132.17 amu. Thus, option D is correct.

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Answer:

This is a waning moon.

Explanation:

Answer:

Its waxing moon

Explanation:

Answer: Hello I was able to find the missing options related to your question online but I couldn't attach them hence I just used them to provide the relevant solution

answer:

Explanation:

OPEN end of the tube down. Continue tapping until the sample. Is a couple of mm high Then, with the Closed end of the tube down, tap the sample down slowly or drop tube into a longer/larger tube to move the sample down faster. Finally, make sure that you can see  sample clearly in the magnifier when placed in the melting point apparatus before turning on the heat.

Answer:

he Paleozoic, Mesozoic, and Cenozoic.

Explanation:

Answer:

Fault-Block Mountain

Explanation:

just did test and got it correct UwU

The geologist is making observation from the fault block mountain so that she sees two parallel faults one from east and another from west.

Mountains with fault blocks are identifiable by their great sheer rock faces. These are created when a large rock mass separates from another due to intense subterranean pressure. The fault is the location on the line where this break occurs.

The rocks rise on one side of this breach and sink on the other. Fault blocks are very large blocks of rock, sometimes hundreds of kilometers in extent, created by tectonic and localized stresses in earth's crust. Large areas of bedrock are broken up into blocks by faults. Blocks are characterized by relatively uniform lithology.

The largest of these fault blocks are called crustal blocks. Large crustal blocks broken off from tectonic plates are called terranes. Those terranes which are the full thickness of the lithosphere are called microplates.

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Answer:

The air being heated by the sun

Explanation:

Just took the quiz

Answer:

The answer is A (the air being heated by the sun)

Explanation:

A P E X

Answer:

To solve this problem, we can use the definition of percent concentration by mass:

percent concentration = (mass of solute ÷ mass of solution) x 100%

We know that the percent concentration of NaCl in the solution is 15% by mass, and we have a 500 gram sample of the solution. Let's assume that the mass of NaCl in the sample is x grams.

Using the percent concentration formula, we can write:

15% = (x ÷ 500) x 100%

Simplifying this equation, we get:

x = (15 ÷ 100) x 500 = 75 grams

Therefore, there are 75 grams of NaCl in a 500 gram sample of the solution.

The correct answer is c. 75 grams.

Answer:

M=0.380 M.

Explanation:

Hello there!

In this case, given those two solutions of aluminum bromide and zinc bromide, it is firstly necessary to compute the moles of bromide ions in each solution as shown below:

\(n_{Br^-}^{in\ AlBr_3}=4.85 gAlBr_3*\frac{1molAlBr_3}{266.69gAlBr_3}*\frac{3molBr^-}{1molAlBr_3} =0.05456molBr^-\\\\n_{Br^-}^{in\ ZnBr_2}=7.75gZnBr_2*\frac{1molZnBr_2}{225.22gZnBr_2}*\frac{2molBr^-}{1molZnBr_2} =0.06882molBr^-\)

Now, we compute the total moles of bromide:

\(n_{Br^-}=0.05456mol+0.06882mol\\\\n_{Br^-}=0.12338mol\)

Then, the total volume in liters:

\(150mL+175mL=325mL*\frac{1L}{1000mL} \\\\=0.325L\)

Therefore, the concentration of total bromide is:

\(M=\frac{0.12338mol}{0.325L}\\\\M=0.380M\)

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