why is space cold ???

Answer:

First and last sentence .‍♀️

Explanation:

An important thing to keep in mind about the Reading Comprehension section of the GRE as we use PowerPrep online to study is that it is just that—reading comprehension. In other words, as difficult as it may seem, and it can be pretty tricky, the test makers will always give us all the information we need in the passage to answer the question.

Answer:

coal

Explanation:

Explanation:

c)The new kinetic energy of each gas particle is the sum of the kinetic energy that each particle is traveling with.

Answer:

175.5

Explanation:

Answer: 1. The empirical formula is [tex]PNF_2[/tex]  

2. The molecular formula is [tex]PNF_2[/tex]

Explanation:

If percentage are given then we are taking total mass is 100 grams.

So, the mass of each element is equal to the percentage given.

Mass of P = 37.32 g

Mass of N = 16.88 g

Mass of F = 45.79 g

Step 1 : convert given masses into moles.

Moles of P =[tex]\frac{\text{ given mass of P}}{\text{ molar mass of P}}= \frac{37.32g}{31g/mole}=1.20moles[/tex]

Moles of N =[tex]\frac{\text{ given mass of N}}{\text{ molar mass of N}}= \frac{16.88g}{14g/mole}=1.20moles[/tex]

Moles of F =[tex]\frac{\text{ given mass of F}}{\text{ molar mass of F}}= \frac{45.79g}{19g/mole}=2.41moles[/tex]

Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.

For P = [tex]\frac{1.20}{1.20}=1[/tex]

For N = [tex]\frac{1.20}{1.20}=1[/tex]

For F =[tex]\frac{2.41}{1.20}=2[/tex]

The ratio of P: N: F= 1: 1: 2  

Hence the empirical formula is [tex]PNF_2[/tex]

The empirical weight of [tex]PNF_2[/tex]= 1(31)+1(14)+2(19)= 82.98 g.

The molecular weight = 82.98 g/mole

Now we have to calculate the molecular formula.

[tex]n=\frac{\text{Molecular weight}}{\text{Equivalent weight}}=\frac{82.98}{82.98}=1[/tex]

The molecular formula will be=[tex]1\times PNF_2=PNF_2[/tex]

Answer:

c. uracil

Explanation:

uracil is not found in DNA. the missing base would be thymine

Answer:

C. 1-ethyl, 3-methylcyclohexane

(Photo for proof at the bottom.)

Explanation:

The 1-ethyl is because you start numbering from the longest branch, towards the next closest branch. Prefix "eth-" means two, there are 2 carbons in the longest branch. 3-methyl is because the next branch is at number 3, and prefix "meth-" means 1, there is 1 carbon in that chain. "Cyclo" in cyclohexane means the skeletal model is shaped like a ring, and the "hexane" means there are 6 carbons in the ring. Prefix "hex" means 6.

Here's a photo of the unit review on Edge. Refer to the 2nd attachment for a visualization.

Please click the heart if this helped.

Answer:

C. 1-ethyl,3-methylcyclohexane

Explanation:

Answer:

As gas is compressed, the individual molecules begin to move in each others way creating a very repulsive force. It acts to oppose any further volume decrease. At very close distances, all molecules repel each other as their electron clouds emerge.

Explanation:

Answer:

0.217 M NaOH

Explanation:

M1V1 = M2V2

M1 = 0.312 M HCl

V1 = 17.4 mL HCl

M2 = ?

V2 = 25.0 mL NaOH

Solve for M2 --> M2 = M1V1/V2

M2 = (0.312 M)(17.4 mL) / (25.0 mL) = 0.217 M NaOH

Explanation:

Na3PO4+ FeCl3 = 3NaCl + FePO4

Hope it will help :)❤

The net ionic equation is found to be balanced by both mass and charge. There are equal masses of each element on the product and reactant sides in a balanced net ionic equation.

A chemical equation which shows only those elements, compounds, and ions which are directly involved in the chemical reaction is defined as the net ionic equation. The net ionic equation give us information about the ions that exists in aqueous medium.

A net ionic equation does not consider the spectator ions. The ions which do not participate in chemical reactions and are seen on both sides of the reactions are called spectator ions.

The complete ionic equation for the given reaction is:

3Na⁺ (aq) + PO₄³⁻ (aq) + Fe³⁺ (aq) + 3Cl⁻ (aq) → 3Na⁺ (aq) + 3Cl⁻ (aq) + FePO₄ (s)

The net ionic equation is:

PO₄³⁻ (aq) + Fe³⁺ (aq) → FePO₄ (s)

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Answer:

[tex]Q=-407kJ[/tex]

Explanation:

Hello there!

In this case, considering that the heat has two forms, sensible (variable temperature) and latent (constant temperature), we can notice that phase changes account for latent heat as the temperature remains the same. In such a way, given the enthalpy of vaporization of water, 40.67 kJ/mol, the enthalpy of condensation (reverse process) is the negative value, -40.67 kJ/mol; therefore, the associated latent heat would be:

[tex]Q=180g*\frac{1mol}{18.02g} *-40.67\frac{kJ}{mol} \\\\Q=-407kJ[/tex]

Best regards!

The answer is

C) -407 kJ d

Answer:

11.1249387366083

Explanation:

you do -log([H+]

Answer:

Explanation:

Chemically identical protons in 1HNMR spectra are protons that are found in the same chemical system and produce one signal in the spectra. Non-equivalent protons are protons that reside in various chemical environments and display different signals.

(a) The provided alkyl halide has four carbons, nine hydrogens, and one chlorine atom, according to the molecular formula. To achieve a single NMR peak, all protons (9 hydrogens) must be in the same chemical environment. That is, the carbon skeleton should be made up of three methyl groups, each bound to a single carbon atom.

As a consequence, the tert-butyl chloride structure can be present. That it has three methyl groups that are all the same and are all bound to the same carbon atom. As a result. A single peak is generated by proton NMR.

(b) The other isomeric variant of C4H9Cl, which has several peaks and a doublet at d3.4, could have a proton at a nearby carbon. And then does it produce a doublet. To create the doublet, two methyl groups should be substituted for the carbon. The value of 3.4 indicates that the protons can be exposed to chlorine. As a result, the compound's composition is iso-butyl chloride.

(c) The compound C4H9Cl can have two protons on adjacent carbons since it has multiple peaks and a triplet at d3,5. And then does it generate a triplet. The meaning of 3.5 indicates that the protons should be exposed to chlorine. As a result, the compound's composition is n-butyl chloride.

(d) The compound C4H9Cl has many peaks, including a methyl group triplet at d1.0 and a methyl group doublet after. It's in the same family as the -CH party. Due to the chlorine atom, this doublet occurs at downfield at 1.5. As a result, the compound's composition is sec-butyl chloride.

Answer:

reactivity

Explanation:

for example atoms in group 7 react by gaining 1 electron to become stable but they do not have the same number of energy levels

Answer:

18.0g of CO₂ are present in 9.16L

Explanation:

To solve this question we must use:

PV = nRT

In order to find the moles of the gas and with its molar mass (44.01g/mol for CO₂) we can find the mass of the gas

Assuming STP conditions:

P = 1atm at STP

V = 9.16L

n are the moles of CO₂

R = 0.082atmL/molK

T = 273.15K

Replacing:

PV / RT = n

1atm*9.16L / 0.082atmL/molK*273.15K = n

0.409 moles = Moles of CO₂

The mass is:

0.409 moles CO₂ * (44.01g / mol) =

Answer:

The average kinetic energy of a particle is proportional to the temperature in Kelvin.

Explanation:

The kinetic molecular theory states that particles of matter are in constant motion and collide frequently with each other as well as with the walls of the container.

The collisions between particles are completely elastic. The kinetic energy of the particles of a body depends on the temperature of the body since temperature is defined as a measure of the average kinetic energy of the particles of a body.

Therefore, the average kinetic energy of a particle is proportional to the temperature in Kelvin.

Four postulates make up the kinetic-molecular theory of gases: A gas is made up of molecules moving randomly all the time. Gas molecules exclusively interact with one another through collisions; they do not apply any other forces. Every gas molecule collision is fully elastic, and all kinetic energy is conserved. Here the correct option is B.

According to the kinetic molecular theory, collisions between gas particles occur in perfect elastic motion and are always in motion. Boyle's and Charles's laws can both be explained by the kinetic molecular theory. Only absolute temperature directly affects a group of gas particles' average kinetic energy.

The collisions between particles are completely elastic. The kinetic energy of the particles of a body depends on the temperature of the body since temperature is defined as a measure of the average kinetic energy of the particles of a body.

Thus the correct option is B.

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Answer: The formula of chromium fluoride is CFr2.

Answer:

Explanation:

are where most bits of broken rock are deposited.

This is because oceans are where most bits of broken rock are deposited.

Answer:

%KCl = 7.05%

%Water = 92.95%

Explanation:

Step 1: Given data

Step 2: Calculate the mass of the solution

The mass of the solution is equal to the sum of the masses of the solute and the solvent.

m = 36 g + 475 g = 511 g

Step 3: Calculate the mass percentage of the solution

We will use the following expression.

%Component = mComponent/mSolution × 100%

%KCl = 36 g/511 g × 100% = 7.05%

%Water = 475 g/511 g × 100% = 92.95%

The longest continuous carbon chain comprises five carbon atoms connected by single bonds, so the root name will be pentane. There is a methyl group (—CH3) attached to carbon 3 (since this molecule is symmetrical, the methyl substituent will always be on carbon 3 regardless of which end you begin counting). Thus, the name of this molecule would be 3-methylpentane.

Answer:

Vapor pressure does not changes , Boiling point of liquid increases.

Explanation:

The external pressure creates the water molecules to move rapidly. The boiling point of liquid will increase as a result of external pressure induced on the surface of the liquid. The temperature must be kept constant to bring the liquid to boil.

The concentration of SO42- ions in the final solution is 0.01 mol L-1.

The neutralisation reaction between sulfuric acid (H2SO4) and sodium hydroxide (NaOH) requires the use of a chemical equation that is balanced:

H2SO4 + NaOH = Na2SO4 + 2H2O

We may deduce from the balanced equation that one mole of H2SO4 reacts with one mole of Na2SO4, meaning that the amount of SO42- ions produced is equal to the amount of H2SO4 utilised.

We may determine how many moles of H2SO4 were used by calculating the amount of 0.05 M H2SO4 solution needed to neutralise 25 mL of NaOH solution:

H2SO4 moles are equal to the product of the volume of H2SO4 (in L) and the concentration of H2SO4 (in mol L-1): 0.03214 L 0.05 mol L-1 = 0.001607 mol

The formation of SO42- ions results in the same amount of moles as the
The resulting solution contains the following amounts of SO42- ions per mole of H2SO4 used:

Moles of SO42- ions/volume of solution (in L) = 0.001607 mol/(0.025 L + 0.03214 L) = 0.01 mol L-1; concentration of SO42- ions (in mol L-1)

As a result, the final solution contains 0.01 mol L-1 of SO42- ions.

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Answer:

As of right now (4-7-2021), the physical science requirement for the SLP certificate must be met by completing coursework in the areas of either chemistry or physics.

Answer:

4.2 mol NH3

Explanation:

First, balance your reaction.

N2 + 3H2 --> 2NH3

Multiply 6.3 mol H2 by the mole ratio of 2 mol NH3 for every 3 mol H2 to get moles of NH3 produced.

6.3 mol H2 • (2 mol NH3 / 3 mol H2) = 4.2 mol NH3