How do I answer the question in bold? Thank you!

Answer:

Theory

Explanation:

We are given the statement;

"A helium filled balloon floats."

Now, this statement is an attempt to explain to us why balloons float. And the reason is because they are filled with helium. This is no prediction or law or observation because to find out if the balloons contain helium, there must have been experiments to confirm that.

Thus, the statement in the question is a theory.

Answer: The first law of thermodynamics is a statement of conservation of energy.

Explanation:

According to the first law of thermodynamics, heat provided to a system is actually the sum of internal energy and work done by the system or on the system.

Mathematically, [tex]\Delta Q = \Delta U + \Delta W[/tex]

The first law of thermodynamics also means that energy can neither be created nor it can be destroyed. Hence, energy is conserved.

Thus, we can conclude that the first law of thermodynamics is a statement of conservation of energy.

Answer:

See explanation

Explanation:

Science as a body of knowledge seeks to understand the processes that occur in nature so as to offer plausible explanations to those processes as well as redesign nature for our benefit.

Hence, science is an inquiry into nature with the aim to improve the life of the general population of the world.

Chemistry is the study of matter and the changes that matter undergoes. Chemistry lies at the very foundation of science since changes in matter is the basis for the processes that occur in nature.

Hence, chemistry plays a critical role in understanding nature as well as amending nature to improve the living condition of the world's rapidly growing population.

Answer:

3 > 2> 1

Explanation:

Aromatic compounds undergo electrophilic substitution reaction which passes through a positively charged intermediate to yield the product.

Substituted benzenes may be more or less reactive towards electrophilic aromatic substitution than benzene molecule depending on the nature of the substituent.

Certain substituents increase the ease of reaction of benzene towards aromatic substitution.

If we look at the compounds closely, we will notice that toluene reacts readily with CH3Cl / AlCl3. This is because, the methyl group is electron donating hence it stabilizes the positively charged intermediate produced in the reaction.

Carbonyl compounds are electron withdrawing substituents hence they decrease the magnitude of the positive charge and hence decrease the rate of electrophilic aromatic substitution.

Answer:

Nuclear

Solar

Wind

Hydro

Geo-Thermal

Explanation:

hope it helps

Answer:

The average mass of one atom of arsenic is 74.92 amu, and the mass of one mole of arsenic atoms is 74.92 grams.

The mass of one mole of arsenic atoms is 74.92 grams.

Calculation,

Mass of one mole of arsenic = Mass of 1 arsenic atom × [tex]N_{A}[/tex]

Where, [tex]N_{A}[/tex] = Avogadro's number = 6.022 × [tex]10^{23}[/tex]

Mass of one arsenic atom = 74.921 u

One u =  1.66 × [tex]10^{-27}[/tex] kg

And,

Mass of one mole of arsenic atom = 6.022 ×[tex]10^{23}[/tex] × 74.921 × 1.66 × [tex]10^{-27}[/tex]×[tex]10^{3}[/tex] kg

Mass of one mole of arsenic atom = 74.92 [tex]gmol^{-1}[/tex]

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Answer:

B. False

Explanation:

Water does NOT react too copper. Copper does not react with water because the oxygen in water is locked into a compound with one part oxygen and two parts hydrogen. Copper oxide is a compound from the two elements copper and oxygen. Everything else listed does but since water is on this list it is false.

Answer:

243.75 mL

Explanation:

In 1min 32.5 mL of oxygen

In 7.5 min electrolysis of water produces

(32.5mL × 7.5 min)/ 1min

= 243.75mL

Answer: The total partial pressure of the solution is 131.37 torr.

Explanation:

The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)

Given mass of glucose = 46.8 g

Molar mass of glucose = 180 g/mol

Plugging values in equation 1:

[tex]\text{Moles of glucose}=\frac{46.8g}{180g/mol}=0.26 mol[/tex]

Given mass of methanol = 117 g

Molar mass of methanol = 32 g/mol

Plugging values in equation 1:

[tex]\text{Moles of methanol}=\frac{117g}{32g/mol}=3.66 mol[/tex]

Mole fraction is defined as the moles of a component present in the total moles of a solution. It is given by the equation:

[tex]\chi_A=\frac{n_A}{n_A+n_B}[/tex] .....(2)

where n is the number of moles

Putting values in equation 2:

[tex]\chi_{methanol}=\frac{3.66}{0.26+3.66}=0.934[/tex]

Raoult's law is the law used to calculate the partial pressure of the individual gases present in the mixture. The equation for Raoult's law follows:

[tex]p_A=\chi_A\times p_T[/tex] .....(3)

where [tex]p_A[/tex] is the partial pressure of component A in the mixture and [tex]p_T[/tex] is the total partial pressure of the mixture

We are given:

[tex]p_{methanol}=122.7torr\\\chi_{methanol}=0.934[/tex]

Putting values in equation 3, we get:

[tex]122.7torr=0.066\times p_T\\\\p_T=\frac{122.7torr}{0.934}=131.37torr[/tex]

Hence, the total partial pressure of the solution is 131.37 torr.

Answer:

C2H4O3

Explanation:

Empirical formula is defined as the simplest whole number ratio of atoms present in a molecule.

To solve this question we need to find the moles of carbon = Moles of CO2, the moles of hydrogen (Using moles of H2O) and the moles of oxygen (Finding the mass of the mass of each atom) as follows:

Moles Carbon -Molar mass CO2: 44.01g/mol-:

33.86g CO2 * (1mol/44.01g) = 0.769 moles CO2 = Moles C * (12g/mol) =

9.23g C

Moles Hydrogen -Molar mass H2O: 18.01g/mol-

13.86g H2O * (1mol/18.01g) = 0.770 moles H2O * (2mol H / 1mol H2O) = 1.54 moles H * (1g/mol) = 1.54g H

Moles Oxygen:

Mass: 29.26g - 9.23g C - 1.54g H = 18.49g O * (1mol/16g) = 1.156 moles O

Dividing each number of moles in the moles of C (Lowe number of moles):

C = 0.769 moles C / 0.769 moles C  = 1

H = 1.54 moles H / 0.769 moles C = 2

O = 1.156 moles O / 0.769 moles C = 1.5

As the number must be a whole number each ratio twice:

C = 2

H = 4

O = 3

Empirical formula is:

Answer:

C₂H₃O

Explanation:

From the question given above, the following data were obtained:

Carbon (C) = 48.8383%

Hydrogen (H) = 8.1636%

Oxygen (O) = 43.1981%

Empirical formula =?

The empirical formula of the compound can be obtained as follow:

C = 48.8383%

H = 8.1636%

O = 43.1981%

Divide by their molar mass

C = 48.8383 / 12 = 4.07

H = 8.1636 / 1 = 8.1636

O = 43.1981 / 16 = 2.7

Divide by the smallest

C = 4.07 / 2.7 = 2

H = 8.1636 / 2.7 = 3

O = 2.7 /2.7 = 1

Thus, the empirical formula of the compound is C₂H₃O

Answer:

Yan po Ang sagot NASA pic

Explanation:

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Answer:

The movement of the earth around the sun in a fixed path or orbit is called Revolution. The axis of the earth which is an imaginary line, makes an angle of 66½° with its orbital plane. ... The earth takes about 24 hours to complete one rotation around its axis.

Answer:

Multiply the number of moles of butane by its molar mass, 58.12g/mol, to produce the mass of butane. Mass of butane = 18.8g.

Complete question:

What mass of steam initially at 120 ⁰C is needed to warm 200g of water in a 100 g glass container from 20.0 oC to 50.0 ⁰C

Answer:

the initial mass of the steam is 10.82 g

Explanation:

Given;

mass of water, m₁ = 200 g

mass of the glass, m₂ = 100 g

temperature of the steam = 120 ⁰C

initial temperature of the water, 20⁰ C

final temperature of the water, = 50⁰ C

let the mass of the steam = m

specific heat capacity of water c = 1 cal/g ⁰ C

specific heat capacity of glass c₂ = 0.2 cal/g ⁰ C

laten heat of vaporization of steam L = 540 cal/g

Apply principle of conservation energy;

Heat given off by the steam = Heat absorbed by water + heat absorbed by glass

[tex]mc\Delta T_1 + mL + mc\Delta T_2 = m_1c\Delta T_3 + m_2c_2\Delta T_3\\\\mc\Delta T_1 + mL + mc\Delta T_2 = [m_1c + m_2c_2]\Delta T_3[/tex]

m(1) (120 - 100)  +  m(540)  + m(1) (100 - 50) = [200(1)  +  100(0.2)] (50 - 20)

20m + 540m + 50m = 6600

610 m = 6600

m = 6600 / 610

m = 10.82 g

Therefore, the initial mass of the steam is 10.82 g

Answer:

S + 2CO = SO2 + 2C

First, look for the amount of substance of sulfur:

n(S) = m / M

n(S) = 14.8 g/32 g / mol = 0.4625 mol

n(CO) = m (CO) / M (CO)

M(CO) = 12 + 16 = 28 g/mol

n(CO) = 19.9 g/28 g/mol = 0.71 mol

S in excess, so for calculating we take CO:

n(SO2) = n(CO)/2 = 0.71 mol/2 = 0.355 mol

m(SO2) = M(SO2)*n(SO2)

M(SO2) = 32 + 16*2 = 64 g/mol

m(SO2) = 64 g/mol * 0.355 mol = 22.74 g

Answer:

3.36 grams Al°(s)  

Explanation:

Given AlCl₃(s), determine the mass (grams) of Al°(s) produced from electrolysis of Aluminum Chloride at 10.0 amps for 1.00 hour.

AlCl₃(s) + 378.3°F (=192.4°C) => Al⁺³(l) + 3Cl⁻(l)

formula wt. Al° = 27g/mol

Faraday Constant (F°) = 96,500 amp·sec

? grams Al°(s) = 10.0amps x (1 mole e⁻/96,500amp-sec) x (1 mole Al°(s)/3 mole e⁻) x (27g Al°(s)/1 mole Al°(s)) x 3,600 sec = 3.36 grams Al°(s)

The 3.36 grams of aluminum are produced in 1 hour by the electrolysis of molten AlCl₃ when 10A current is passed.

Electrolysis is a process that uses an electrical current to break chemical compounds. The electric current is passed through the substance to bring the chemical change by gain or loss of electrons.

The electrolysis of the aluminum chloride in the molten state is represented as:

AlCl₃  →   Al³⁺    +  3Cl⁻

At cathode:   Al³⁺  +  3e⁻  →  Al (s)

Given,  the current. I = 10 A and  t = 1 hr = 3600 s

We know that the current is calculated from the equation:  I = q/t

q = I× t

q = (10A) × (3600s)

q = 36 × 10³ C

We know, 96500 C of the charge has electrons = 1 mol

36 × 10³ C of the charge has electrons  = 0.373 mol

3 moles of electrons required to produce aluminum = 1 mol

0.373 mol of electrons will produce aluminum = 0.373/3 = 0.124 mol

We know that, the mass of one mole of Al = 27g

The mass of 0.124 mol of Al = 27 × 0.124 = 3.36 g

Therefore, the aluminum produced in 1 hour by the electrolysis of molten AlCl₃ is equal to 3.36 grams.

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Answer:

The kinds of intermolecular forces that are present in each element Kr-Kr.

Explanation:

Since Kr is an inert gas and in atomic form only it is highly stable.

So, Kr gas does not form molecules.

Between the atoms of inert gas, there exist London dispersion forces.

Hence, the intermolecular forces that are present between Kr-Kr atoms is London dispersion forces.

Answer:

I expect to observe a change in colour from reddish brown to a colourless solution

Explanation:

Bromine (Br2) attacks the electron rich carbon-carbon triple bond in but-2-yne, an alkyne to form an initial product 2, 3 dibromobut-2-ene; which reacts with excess bromine to form a final product 2,2,3,3 -tetrabromobutane.

The reaction occurs in two steps. On approaching but-2-yne, bromine molecule becomes polarised forming an induced dipole containing a bromonium ion.

Br - Br → Br+ - Br-

The bromonium ion (Br+) formed then attacks the carbon - carbon triple bond to form the initial product

2,3- dibromobut-2-ene

CH2-C≡C-CH2 + Br+ →

CH2 - CBr =CBr-CH2

(2,3- dibromobut-2-ene)

Which in the presence of excess bromine gives the final product

2,2,3,3 - tetrabromobutane.

CH2 - CBr =CBr-CH2 + Br2 →

CH3 -CBr2-CBr2 - CH3

2,2,3,3 - tetrabromobutane.

A visible change in colour from the reddish-brown colour of Bromine to a colourless solution is observed during the reaction.

Answer: There are 8 protons in oxygen-18 and 36 neutrons in copper-65.

Explanation:

An atom contains three sub-atomic particles, that is, protons, neutrons and electrons.

The atomic number is the total number of protons present in an atom. For oxygen-18, the atomic mass is 18.

Atomic mass is the sum of total number of protons and electrons present in an atom. As the atomic number of an oxygen atom is 8 so the number of protons present in oxygen-18 is 8.

The atomic mass of copper is 65 and for a copper atom, the atomic number is 29. Hence, the number of neutrons for copper-65 is as follows.

Atomic mass = no. of protons + no. of neutrons

65 = 29 + no. of neutrons

no. of neutrons = 65 - 29 = 36

Thus, we can conclude that there are 8 protons in oxygen-18 and 36 neutrons in copper-65.

Answer:

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ASAP PROJECT

Answer:

When this equation is solved, the two values of the unknown are 0.0643 and -0.082

Explanation:

Given

[tex]1.77 * 10^{-2} = \frac{x^2}{0.298 - x}[/tex] --- the actual equation

Required

The values of x

We have:

[tex]1.77 * 10^{-2} = \frac{x^2}{0.298 - x}[/tex]

Cross Multiply

[tex]1.77 * 10^{-2} * (0.298 - x)= x^2[/tex]

Multiply both sides by 100

[tex]1.77 * (0.298 - x)= 100x^2[/tex]

Open bracket

[tex]0.52746 - 1.77x= 100x^2[/tex]

Rewrite as:

[tex]100x^2 + 1.77x - 0.52746 =0[/tex]

Using quadratic formula:

[tex]x = \frac{-b \± \sqrt{b^2 - 4ac}}{2a}[/tex]

Where:

[tex]a = 100; b = 1.77; c = -0.52746[/tex]

So, we have:

[tex]x = \frac{-1.77 \± \sqrt{1.77^2 - 4*100*- 0.52746 }}{2*100}[/tex]

[tex]x = \frac{-1.77 \± \sqrt{214.1169}}{2*100}[/tex]

[tex]x = \frac{-1.77 \± 14.63}{200}[/tex]

Split

[tex]x = \frac{-1.77 + 14.63}{200}\ or\ x = \frac{-1.77 - 14.63}{200}[/tex]

[tex]x = \frac{12.86}{200}\ or\ x = \frac{-16.40}{200}[/tex]

[tex]x = 0.0643\ or\ x = -0.082[/tex]

i can not understand the question. There seems to be missing info

Answer:

The mass of bromine liquid that participates in  a chemical reaction=12.8 g

Explanation:

We are given that

Total number of moles of bromine liquid participate in chemical reaction=0.0800 moles

We have to find the mass of bromine liquid that participates.

Atomic mass of Br=79.9 g

1  mole of bromine liquid=2 atomic mass of bromine (Br)

1 mole of bromine liquid ([tex]Br_2[/tex]) =[tex]2\times 79.9=159.8 g[/tex]

0.0800 moles of  bromine liquid=[tex]159.8\times 0.0800[/tex] g

0.0800 moles of  bromine liquid=12.784 g

0.0800 moles of  bromine liquid[tex]\approx 12.8[/tex] g

Hence, the mass of bromine liquid that participates in  a chemical reaction=12.8 g

Explanation:

here is the answer to your question.

Answer:

Pressure increases

Explanation:

Boyle's law states that; '' the volume of a given mass of ideal gas is inversely proportional to its pressure at constant temperature.

Hence, when the volume of a given mass of ideal gas is decreased, the molecules of the gas come closer together so they collide with each other and the walls of the container more frequently.

This implies that the pressure of the gas increases as volume decreases in accordance with Boyle's law.

Answer:

C₂H₆(g) + 2.5 O₂(g) ⇒ 2 CO(g) + 3 H₂O(g)

Explanation:

Let's consider the unbalanced equation in which gaseous ethane reacts with gaseous oxygen to form carbon monoxide gas and water vapor. This is an incomplete combustion reaction.

C₂H₆(g) + O₂(g) ⇒ CO(g) + H₂O(g)

We will balance it using the trial and error method.

First, we will balance C atoms by multiplying CO by 2 and H atoms by multiplying H₂O by 3.

C₂H₆(g) + O₂(g) ⇒ 2 CO(g) + 3 H₂O(g)

Then, we get the balanced equation by multiplying O₂ by 2.5.

C₂H₆(g) + 2.5 O₂(g) ⇒ 2 CO(g) + 3 H₂O(g)

Answer:

0.043 M

Explanation:

The reaction that takes place is:

First we calculate how many HCl moles reacted, using the given concentration and volume required to reach the equivalence point:

As 1 mol of H⁺ reacts with 1 mol of OH⁻, in the 25.0 mL of the Ca(OH)₂ sample there are 1.0817 mmoles of OH⁻.

With that in mind we can calculate the hydroxide ion concentration in the original sample solution, using the calculated number of moles and given volume:

The titration is termed the neutralization reaction with the acid and base. The concentration of hydroxide in the titration is 0.0865 M.

The neutralization reaction is given as the reaction in which the acid and base react to form the salt and water, stabilizing the pH of the solution.

The neutralization of acid and base to identify the strength can be given as:

[tex]\rm M_V_1=M_2V_2[/tex]

Substituting the strength and the volume of calcium hydroxide and the HCl with the volume:

[tex]\rm 0.029\;M\;\times\;37.3\;mL=M_2\;\times\;25\;mL\\M_2=\dfrac{ 0.029\;M\;\times\;37.3\;mL}{25\;mL} \\M_2=0.0432\;M[/tex]

The strength of the calcium hydroxide in the reaction is 0.04326 M.

One molar unit of calcium hydroxide results in 2 molar units of hydroxide. The molar unit of hydroxide in 0.04326 M calcium hydroxide is:

[tex]\rm 1\;M\;Ca(OH)_2=2\;M\;OH^-\\\\0.04326\;M\;Ca(OH)_2=0.04326\;\times\;2\;M\;OH^-\\0.04326\;M\;Ca(OH)_2=0.0865\;M\;OH^-[/tex]

The concentration of hydroxide ion in the titration is 0.0865 M.

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Answer:

7.44 C is the answer of the question.

Explanation:

Answer:

e. The lipid bilayer is a permeability barrier for integral membrane proteins.

Explanation:

Integral membrane proteins enter the lipid bilayer by translocon channel which gives nascent polypeptide segment a chance to partition itself into lipid bilayer hydrophobic core.