Please someone can help with this answer?

Answer:

148.04 kJ/mol

Explanation:

Let's consider the following thermochemical equation.

NO(g) + 1/2 O₂(g) → NO₂(g)      ΔH°rxn = -114.14 kJ/mol

We can find the standard enthalpy of formation (ΔH°f) of NO(g) using the following expression.

ΔH°rxn = 1 mol × ΔH°f(NO₂(g)) - 1 mol × ΔH°f(NO(g)) - 1/2 mol × ΔH°f(O₂(g))

ΔH°f(NO(g)) = 1 mol × ΔH°f(NO₂(g)) - ΔH°rxn - 1/2 mol × ΔH°f(O₂(g)) / 1 mol

ΔH°f(NO(g)) = 1 mol × 33.90 kJ/mol - (-114.14 kJ) - 1/2 mol × 0 kJ/mol / 1 mol

ΔH°f(NO(g)) = 148.04 kJ/mol

Answer:

The answer is Option A = CCl2F2

The chemical formula for an organic molecule is CCl2F2. The correct option is A.

An organic molecule is a complicated compound that is chiefly comprised of carbon atoms bonded with other elements and another carbon atoms.

All lifeforms on Earth are comprised of organic molecules. A molecule is a cluster of atoms which are basically bonded together.

Molecules other than organic molecules is referred to as inorganic molecule. These are basically simple and are not usually encountered in living things.

Although all organic substances encompasses carbon, some substances containing carbon, such as diamonds, are taken as inorganic.

Organic compounds as well as inorganic compounds develops the basis of chemistry.

The chief distinction between organic and inorganic compounds is that organic compounds always contain carbon while most inorganic compounds do not encompass carbon.

Also, perhaps all organic compounds contain carbon-hydrogen or C-H bonds.

Thus, the correct option is A.

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Answer:

NH3

Explanation:

A hydrogen bond donor is the supplier of the hydrogen atom that is involved in the hydrogen bonding interaction.

A hydrogen bond acceptor is the electronegative atom that 'accepts' the hydrogen in the hydrogen bond. Such electronegative atoms usually possess an unshared pair of electrons such as nitrogen.

We can see from the above definitions that NH3 is able to act in the capacity of a hydrogen bond donor(due to the presence of three N-H bonds) or as a hydrogen bond donor due to presence of an unshared pair on nitrogen atom.

Answer:

0.0452

Explanation:

Its Grams and milligrams.Just like dividing by ten, except 3 times.

Answer:

Coarse and fine adjustment The coarse adjustment knob should only be used with the lowest powerobjective lens. Once it is in focus, you will only need to use the fine focus. Using the coarse focus withhigher lenses may result in crashing the lens into the slide.

Answer:

Explanation:

mass = 8.37 grams

volume = 23.1 - 20.0 = 3.1 mL

density = mass / volume

density = 8.37 / 3.10 = 2.70

Be sure and add the 0 in your answer. You have 3 places of significant digits.

Answer:

The water/alcohol solvent caused the dots to move the most. The oil solvent

Explanation:

Answer:

Tens place

Ones place

69.5 ml

Explanation:

Hi! Sorry about your frustration.

Looking at the attachment again, I can then say that

3a) the answer would be only tens place. You may think ones place is correct, but then again look at the beaker. Are there any measurement in ones graduated on it? The question says "certain", while it's possible to calculate in ones, you most likely would be guessing and not certain about it.

3b) from the explanation I did in 3a above, it is thus clear ones place is the answer here. Calculating in tens is very certain, calculating in tenth and hundredth place is quite hard, if not impossible. Therefore, ones place is possible, but uncertain.

3c) If both 68 & 69 are incorrect, I'd advise you try something even much closer to 70, in 69.5

Kindly vote brainliest, thanks

Answer:

Yes, the 4 Krabby patties are an example of high precision.

Explanation:

Precision is the closeness of the values ​​obtained by applying them to the same parameter. To calculate the precision, the closeness of each of the values ​​with the mean must be determined, all the values ​​will be taken by subtracting the mean and the values ​​will be taken into account to know which are the most accurate.

(12.12 + 11.9 + 12.2 + 12. 1) / 4 = 12.08

12.12 - 12.8 = 0.04

11.9 - 12.08 = - 0. 18

12.2 - 12.08 = 0.12

12.1 - 12.08 = 0.02

The most accurate precision is that of the fourth Krabby Pattie and the least precise is that of the second.

Explanation:

Step 1:  Determine what precision and accuracy is

According to online, "precision is how close measure values are to each other, basically how many decimal places are at the end of a given measurement. Precision does matter. Accuracy is how close a measure value is to the true value. Accuracy matters too, but it's best when measurements are both precise and accurate."

Step 2:  Determine which are displayed in this problem

We can see that most of these weight are really close to the original weight which means that the accuracy is pretty high.  This means that our weights are fairly close to the original predicated amount.

We can also see that our precision is somewhat decent because most of the numbers bunch up around each other.  Precision and accuracy don't have to occur at the same time.  For example, a precise collection can be 15, 15.01, 14.99.  Although they are far away from the original point, they are bunched up together giving a high precision.

Answer:

3 Significant Figures

Explanation:

the significant figures in 0.000657 are 6, 5, and 7.

Answer:

[tex]m_{Be}=51.3gBe[/tex]

Explanation:

Hello,

In this case, with the given chemical reaction:

[tex]Be(s) + 2H_2 O(l) \rightarrow Be(OH)_ 2 (aq) + H _2 (g)[/tex]

We can notice a 1:1 mole ratio between hydrogen gas and beryllium metal, therefore, beryllium requirement is computed as shown below:

[tex]m_{Be}=11.5gH_2*\frac{1molH_2}{2.02gH_2} *\frac{1molBe}{1molH_2} *\frac{9.01gBe}{1molBe}\\ \\m_{Be}=51.3gBe[/tex]

Regards.

Answer:

3.3 cm³

Explanation:

Use the density formula, d = m/v, to solve for the volume:

2.7 = 9.0/v

2.7v = 9.0

v = 3.3 cm³

Answer:

166 g

Explanation:

Step 1: Write the reaction for the obtaining of Fe from magnetite

Fe₃O₄ ⇒ 3 Fe + 2 O₂

Step 2: Calculate the moles corresponding to 120 g of Fe

The molar mass of Fe is 55.85 g/mol.

120 g × (1 mol/55.85 g) = 2.15 mol

Step 3: Calculate the moles of Fe₃O₄ required to produce 2.15 moles of Fe

The molar ratio of Fe₃O₄ to Fe is 1:3. The moles of Fe₃O₄ required are 1/3 × 2.15 mol = 0.717 mol

Step 4: Calculate the mass corresponding to 0.717 moles of Fe₃O₄

The molar mass of Fe₃O₄ is 231.53 g/mol.

0.717 mol × 231.53 g/mol = 166 g

Answer:

Hey!

39 / 24.2 = 943.8

Explanation:

943.8 to 2 s.f (best option for rounding)

= 940

ANSWER = 940

HOPE THIS HELPS!

Answer:

The direction will be changed .

Explanation:

According to the principles of motion, if an object is moving with solitary velocity and if an external force is applied to it, then that force changes the position, speed, and direction of that object.

In the given question, an external force is being applied to the toy which will change the direction of that toy.

Answer:

See attached picture.

Explanation:

Hello,

In this case, for the given name, you can verify the structure on the attached picture, wherein you can see verify the presence of both the ethyl and methyl radicals at the third carbon as well as the triple bond at the first carbon.

Best regards.

Answer: 41 7/10

Explanation:  The mark is on the seventh out of ten marks

Answer:

molecules are the groups of atom bonding together , representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction

Answer:

trigonal pyramidal

Explanation:

There are two characteristics of molecules, one is geometry and other is shape. Shape is excluding lone pair surrounding the central element and geometry is including the lone pair. Therefore, the  word or two-word phrase best describes the shape of the phosphorus trifluoride ( PF[tex]_3[/tex]) molecule is trigonal pyramidal.

VSEPR stands for valence shell electron pair repulsions. VSEPR theory is used to predict the shape and geometry of molecules on the basis of valence electrons pairs that are present around the central element of the molecule.

According to VSEPR theory, Lone pair lone pair repulsion is greater than bond pair bond pair repulsion. There are so many limitations of VSEPR theory. There is a repulsion between bond pair electrons and lone pairs present on the central element. The  word or two-word phrase best describes the shape of the phosphorus trifluoride ( PF[tex]_3[/tex]) molecule is trigonal pyramidal.

Therefore, the  word or two-word phrase best describes the shape of the phosphorus trifluoride ( PF[tex]_3[/tex]) molecule is trigonal pyramidal.

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Answer:

hydration reaction

Explanation:

The type of reaction would be hydration reaction.

Hydration reaction generally involves a chemical reaction of water with another reactant and in which the water ends up being converted to another product entirely.

A good example of hydration reaction is the reaction between alkene and water leading to the production of alcohol.

[tex]CH_2=CH_2(g) + H_2O(g)[/tex]  ⇄  [tex]CH_3CH_2OH(g)[/tex]

Answer:

the answer would be hydrolysis, as found on the test and verified by google experts.

Answer:

pH = 7.73

Explanation:

The pKa of the HOCl/KOCl buffer is 7.46. To determine the pH of this buffer we can use H-H equation:

pH = pKa + log [A⁻] / [HA]

pH = 7.46 + log [KOCl] / [HOCl]

Where [] is molarity -or moles- of each compound

Initial moles of HClO and NaClO:

HOCl: 0.500L * (0.12mol / L) = 0.06 moles HOCl

KOCl: 0.500L * (0.080mol / L) = 0.04 moles KOCl

Now, HOCl reacts with KOH producing KOCl:

HOCl + KOH → KOCl + H₂O

The moles of KOH in the reaction are:

2.5x10⁻³L * (10mol /L) = 0.025 moles KOH

That means after the reaction, 0.025 moles of HOCl are consumed and 0.025 moles of KOCl are produced.

And after the reaction, moles are:

Final moles:

HOCl: 0.06mol - 0.025mol = 0.035 mol

KOCl: 0.04mol + 0.025mol = 0.065 mol

Replaing in H-H equation:

pH = 7.46 + log [0.065mol] / [0.035mol]

Answer:

Copper (cu)

Explanation:Copper (Cu), chemical element, a reddish, extremely ductile metal of Group 11 (Ib) of the periodic table that is an unusually good conductor of electricity and heat. Copper is found in the free metallic state in nature. This native copper was first used (c. 8000 BCE) as a substitute for stone by Neolithic (New Stone Age) humans.

. Metallurgy dawned in Mesopotamia as copper was cast to shape in molds (c. 4000 BCE), was reduced to metal from ores with fire and charcoal, and was intentionally alloyed with tin as bronze

atomic number 29

atomic weight 63.546

melting point 1,083 °C (1,981 °F)

boiling point 2,567 °C (4,653 °F)

density 8.96 at 20 °C (68 °F)

valence 1, 2

electron configuration 2-8-18-1 or (Ar)3d104s1

Copper is one of the most ductile metals, not especially strong or hard. Strength and hardness are appreciably increased by cold-working because of the formation of elongated crystals of the same face-centred cubic structure that is present in the softer annealed copper.

Copper (Cu), chemical element, a reddish, extremely ductile metal of Group 11 (Ib) of the periodic table that is an unusually good conductor of electricity and heat. Copper is found in the free metallic state in nature. This native copper was first used (c. 8000 BCE) as a substitute for stone by Neolithic (New Stone Age) humans.  Metallurgy dawned in Mesopotamia as copper was cast to shape in molds (c. 4000 BCE), was reduced to metal from ores with fire and charcoal, and was intentionally alloyed with tin as bronze

atomic number 29

atomic weight 63.546

melting point 1,083 °C (1,981 °F)

boiling point 2,567 °C (4,653 °F)

density 8.96 at 20 °C (68 °F)

valence 1, 2

electron configuration 2-8-18-1 or (Ar)3d104s1

Copper is one of the most ductile metals, not especially strong or hard. Strength and hardness are appreciably increased by cold-working because of the formation of elongated crystals of the same face-centred cubic structure that is present in the softer annealed copper.

You should research it on quizlet.

Answer:

True

Explanation:

A hypothesis is an educated guess about the outcome of an experiment or thought

Answer:

[tex]m_{solution}=446.4g[/tex]

Explanation:

Hello,

In this case, by-mass percent is computed in terms of the mass of the solute and the mass of the solvent as shown below:

[tex]\% m=\frac{m_{solute}}{m_{solution}} *100\%[/tex]

Thus, solving for the mass of the solution, we obtain:

[tex]\frac{x}{y} m_{solution}=\frac{m_{solute}}{\% m}*100\%\\ \\m_{solution}=\frac{62.5g}{14.0\%}*100\% \\\\m_{solution}=446.4g[/tex]

Regards.

Answer:

13.44 dm³ of hydrogen is needed for the reaction.

(D) is correct option

Explanation:

Given that,

Mass of  copper(II) oxide = 47.7 g

We know that,

Molar mass of CuO = 63.5 + 16 = 79.5 g/mol

We need to calculate the number of moles in 47.7g of copper(II) oxide,

Using formula of moles

[tex]mole=\dfrac{mass}{molar\ mass}[/tex]

Put the value into the formula

[tex]moles=\dfrac{47.7}{79.5}[/tex]

[tex]moles=0.6\ mole[/tex]

Now, we write the balanced equation for the reaction

[tex]CuO+H_{2}\Rightarrow Cu+H_{2}O[/tex]

Here, one mole of CuO reacted with one mole of hydrogen to produce one mole of Cu and one mole of water.

We need to calculate the number of moles of hydrogen needed to react  with 0.6 mole of copper(II) oxide

Using the balanced equation,

1 mole of CuO reacted with 1 mole of Hydrogen.

Therefore, 0.6 mole of CuO will also react with 0.6 mole of hydrogen.

We need to calculate the volume of  occupied by 0.6 mole of H2 at STP

Using formula of volume

[tex]n=\dfrac{V}{V'}[/tex]

Where, n = mole of hydrogen

V = occupied volume

V'= volume at STP

Put the value into the formula

[tex]0.6=\dfrac{V}{22.4}[/tex]

[tex]V=0.6\times22.4[/tex]

[tex]V=13.44\ dm^3[/tex]

Hence, 13.44 dm³ of hydrogen is needed for the reaction.

Answer:

The internal combustion engine in the car converts the potential chemical energy in gasoline and oxygen into thermal energy which is transformed into the mechanical energy that accelerates the vehicle (increasing its kinetic energy) by causing the pressure and performing the work on the pistons.

Answer:

A, B, and C are the correct options.

Explanation:

I just did it on Edge2023

Answer:

Physical change are the temporary reversible change in which no new substance is formed.

Example: boiling of milk, melting of wax, cooling water,etc.

The final temperature of the mixture will be "305.6 K".

According to the question,

Mass of water, m₁ = 30.0 mL or,

                              = 30.0 mL × 1 g/mL

                              = 30.0 g

and,

                        m₂ = 50.0 mL × 1 g/mL

                              = 50.0 g  

Specific heat of water = 4.18 J/g°C

We know the relation,

→ Heat lost + Heat gained = 0

By substituting the values,

  30.0 × 4.18 (T - 282) + 50.0 × 4.18 (T - 320) = 0  

30.0 × 4.18T - 1178.76 + 50.0 × 4.18T - 1337.6 = 0

hence,

The final temperature will be:

                                        T = 305.6 K

Thus the answer above is appropriate.

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