The energy from 0.015 moles of octane was used to heat 250 grams of water. The temperature of the water rose from 293.0 K to 371.2 K. What is the enthalpy of combustion of octane? The specific heat capacity of water is 4.18 J/K g.

A. -5448 kJ/mol
B. 1226 kJ/mol
C. -1226 kJ/mol
D. 293.25 kJ/mol

Answer:

The equation is CuCO₃ ⇆ CuO + CO₂. So it's a decomposition reaction, so a solid broke down into two other substances. This means that bonds were broken, so the reaction must be endothermic.

Answer:

Calcium chloride

Explanation:

Sublimation is the process whereby a solid substance is converted to gas when heat is applied or when exposed to an environment with a higher temperature.

Solid normally gets converted to the liquid phase before reaching the gaseous phase but these substances gets converted from solid straight to gas

Solid—> Gas

Dry ice( solid CO2) and Ammonium chloride undergo sublimation while Calcium chloride doesn't.

Answer:

1. Methyl propanoate.

2. Propanol.

3. 2–pentyne

Explanation:

1. The functional group in this case is ester. We name ester by naming the group after the functional group (–COO) then followed by the parent compound with the name ending with –oate.

The group after the functional is methyl i.e —CH3.

The parent compound has 3 carbon i.e propane. The functional group replaces the –e in propane with –oate.

Therefore, the name of the compound is:

Methyl propanoate.

2. In this case the functional group is

–OH i.e alcohol.

The compound has 3 carbon i.e propane. The functional group replaces the –e in propane with –ol.

Therefore, the name of the compound is:

Propanol.

3. The triple bond represents the functional group in this case i.e alkyne. We'll give the triple bond the lowest low count by counting from the left. The triple bond is at carbon 2.

The compound has 5 carbon i.e pentyne since it contains triple.

The name of the compound is:

2–pentyne

Answer:

The balanced equation is: 2AgNO₃ + MgCl₂ ------> 2AgCl + Mg(NO₃)₂

Explanation:

The law of conservation of mass states that in a normal chemical reaction, matter is neither created nor destroyed.

According to the law of conservation of mass, therefore, when a chemical reaction occurs, the mass of the products should be equal to the mass of the reactants. This implies that the amount of the atoms in each element in the chemical reaction remains the same before and after the reaction. A balanced chemical equation therefore,  is one that shows that the number of the atoms involved in the reactants side is equal to the number of atoms in the products side.

Considering the given reaction:

2AgNO₃ + MgCl₂ ------> 2AgCl + Mg(NO₃)₂

The amount in moles of each atom in the reaction is as follows;

Ag = 2 moles of atom on each side

N = 2 moles of atoms on each side

O = 6 moles of atoms on each side

Mg = 1 mole of atoms on each side

Cl = 2 moles of atoms on each side

Therefore, the above chemical equation is balanced.

Answer:

The equation is already balanced.

Explanation:

Answer:

2,2- dichloro-heptane

Explanation:

The IUPAC name of the compound is 2,2-dichloro-heptane

Answer:

C. the substance in which the solute dissolves

Explanation:

There are two terms in this... the solute and the solvent. The way I learned how to remember this is with a little pirate analogy: The loot (stolen treasure) always goes in the vent. So, the soLUTE goes in the solVENT.

Answer:

[tex]\large \boxed{\text{-92 $^{\circ}$C}}[/tex]

Explanation:

We can use the Ideal Gas Law and solve for T.

pV = nRT

Data  

p = 1.25 atm

V = 25.0 L

n = 2.10 mol

R = 0.082 06 L·atm·K⁻¹mol⁻¹

Calculations

1. Temperature in kelvins

[tex]\begin{array} {rcl}pV & = & nRT\\\text{1.25 atm} \times \text{25.0 L} & = & \rm\text{2.10 mol} \times 0.08206 \text{ L}\cdot\text{atm}\cdot\text{K}^{-1}\text{mol}^{-1} \times T\\31.25&=&0.09847T\text{ K}^{-1}\\T& = &\dfrac{31.25}{\text{0.098 47 K}^{-1}}\\\\& = &\text{181 K}\end{array}[/tex]

2. Temperature in degrees Celsius

[tex]\begin{array} {rcl}T & = & (181 - 273.15) \, ^{\circ}\text{C}\\& = & -92 \, ^{\circ}\text{C}\\\end{array}\\\text{The temperature of the gas is $\large \boxed{\mathbf{-92 \, ^{\circ}}\textbf{C}}$}[/tex]

Answer:

It depends what formula you are talking about.

Explanation:

please further explain so I can be sure.

Answer:

created an organizational hierarchy

Explanation:

Answer: Significant figures in a measurement are all measured digits, and one estimated digit

Significant figures communicate the level of precision in measurements Significant figures are an indicator of the certainty in measurements.

Explanation:

Significant figures : The figures in a number which express the value or the magnitude of a quantity to a specific degree of accuracy or precision is known as significant digits.

The significant figures of a measured quantity are defined as all the digits known with certainty and the first uncertain or estimated digit.

Rules for significant figures:

1. Digits from 1 to 9 are always significant and have infinite number of significant figures.

2. All non-zero numbers are always significant.

3. All zero’s between integers are always significant.

4. All zero’s preceding the first integers are never significant.

5. All zero’s after the decimal point are always significant.

The true statements are

Significant figures in measurement are all measured digits, and one estimated digit

Significant figures communicate the level of precision in measurements Significant figures are an indicator of the certainty in measurements.

The following information should be considered:

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Answer:

No

Explanation:

The pH scale is a scale graduated from 0-14 which shows the degree of acidity of alkalinity of a substance. The pH scale is graduated in such a way that 0-6.9 indicates acidity, 7.0 indicate a neutral substance, while a pH of 8-14 indicates alkalinity respectively.

There are three main definitions of acids/bases

- Arrhenius definition

-Brownstead-Lowry definition

-Lewis definition

Arrhenius explains acids as any substance that produces hydrogen ions as its only positive ion in solution while a base produces hydroxide ions as its only negative ion in solution. The pH scale is based on corresponding values of pH derived from aqueous solutions of these substances.

However, not all acids/bases produces hydrogen or hydroxide ions in solution. Brownstead-Lowry definition of acids and Lewis definition of acids could be extended to nonaqueous media where the pH can not be measured as there are no hydrogen or hydroxide ions present in the solution.

This implies that pH measurement may not apply to acids/bases in the all the categories of acids/bases hence it can not be utilized for all acids and bases.

Arrhenius - sodium carbonate

Brownstead-Lowry - concentrated HF

Lewis acid - AlCl3

Answer:

B. 75.0 kPa

Explanation:

P1V1/T1=P2V2/T2

(x * 100 L)/(300 K)=(100 kPa * 50.0 L)/(200 K)

x=75.0 kPa

Answer:

24rq3r54

Explanation:

3t5q6tq6tq

Answer:

1 mole of nitrogen (N2) reacts with 3 moles of hydrogen (H2) to form 2 moles of ammonia (NH3) ... 4 NH3 (g) + 5 O2 (g) --> 4 NO (g) + 6 H2O (g) ... Example: What is the molar ratio between Li and N2 in the following reaction

Explanation:

1 mole of nitrogen (N2) reacts with 3 moles of hydrogen (H2) to form 2 moles of ammonia (NH3) ... 4 NH3 (g) + 5 O2 (g) --> 4 NO (g) + 6 H2O (g) ... Example: What is the molar ratio between Li and N2 in the following reaction

Answer:

HNO3 ->NO3²- + H+

Concentration of H+ ions= 0.0032M

pH = - log[ H+]

= - log (0.0032)

= 2.49

pH + pOH = 14

pOH = 14 - pH

= 14 - 2.49

= 11.51

pH = 2.49 and pOH = 11.51

Hope this helps.

Answer:

a) [COHNH₂] = 0.001 mol/L, [NH₃] = [CO] = 0.085 mol/L

b) 5.59 atm

Explanation:

a) The decomposition reaction of formamide is the following:

COHNH₂(d)  ⇆  NH₃(g) + CO(g)    

The equilibrium constant of the reaction above is:

[tex]K_{c} = \frac{[NH_{3}][CO]}{[COHNH_{2}]} = 4.84 (400 K)[/tex]

The initial concentration of formamide is:

[tex] C_{COHNH_{2}} = \frac{\eta}{V} = \frac{0.186 moles}{2.16 L} = 0.086 mol/L [/tex]

Where: η is the number of moles and V is the volume

Now, in the equilibrium the concentration of all species is:

COHNH₂(d)  ⇆  NH₃(g) + CO(g)  

0.086 - x              x             x

[tex] K_{c} = \frac{[NH_{3}][CO]}{[COHNH_{2}]} = \frac{x*x}{0.086 - x} [/tex]  

[tex] 4.84*(0.086 - x) -x^{2} = 0 [/tex]

By solving the above equation for x we have:

x = 0.085 mol/L = [NH₃] = [CO]

[COHNH₂] = 0.086 - 0.085 = 0.001 mol/L

Therefore, the concentrations of all species present at equilibrium at 400 K is [NH₃] = [CO] = 0.085 mol/L and [COHNH₂] = 0.001 mol/L.

b) To find the total pressure in the container we need to find first the constant Kp as follows:

[tex] K_{p} = K_{c}*RT^{\Delta n} [/tex]

Where R is the gas constant = 0.082 Latm/(Kmol), T is the temperature = 400 K and Δn = 1

[tex] K_{p} = K_{c}*RT^{\Delta n} = 4.84*(0.082*400)^{1} = 158.8 [/tex]

Now, the total pressure is:

[tex] p_{T} = p_{COHNH_{2}} + p_{NH_{3}} + p_{CO} [/tex]

The pressure of COHNH₂ can be found using Ideal Gas Law:

[tex] P = \frac{nRT}{V} = \frac{0.186 moles*0.082 L*atm/(K*mol)*400 K}{2.16 L} = 2.82 atm [/tex]

Using the equilibrium constant we can find the pressure of NH₃ and CO:

COHNH₂(d)  ⇆  NH₃(g) + CO(g)  

2.82 - x              x             x

[tex] K_{p} = \frac{P_{NH_{3}}*P_{CO}}{P_{COHNH_{2}}} [/tex]

[tex] 158.8*(2.82 - x) - x^{2} = 0 [/tex]

By solving the above equation for x we have:

[tex] x = P_{NH_{3}} = P_{CO} = 2.77 atm [/tex]

[tex] P_{COHNH_{2}} = 2.82 - 2.77 = 0.05 atm [/tex]

Thus, the total pressure is:

[tex] p_{T} = p_{COHNH_{2}} + p_{NH_{3}} + p_{CO} = (0.05 + 2.77 + 2.77) atm = 5.59 atm [/tex]

Hence, the total pressure in the container at equilibrium is 5.59 atm.

I hope it helps you!

Answer:

people are mostly exposed to chemicals through their nose, mouth, eyes, and ears

Explanation:

they are the easiest way for anything, bad or good, to enter the body because  people touch their face alot.

This might not answer what you were looking for but the other answer covered it pretty well so I thought I'd give you another angle to the question!

Hope this helps!!

Answer:

Heat travels faster in solids.

Heat travels slower in gases.

Explanation:

The state of matter in which heat travels in fastest way is solid and in gaseous state heat travels in slowest way.

Heat transfer is a process in which heat can travel from one body to another body or from high temperature to low temperature.

In solid state heat will travel in the fastest way because molecules are arranged very close to each other and heat will travel through conduction process. And in gaseous state heat will travel with slowest way as molecules are arranged in very distance.

Hence in solid, heat travels in fastest way and in gases heat travels in slowest way.

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Answer:

0.75 M

Explanation:

Molarity = moles of solute / liters of solution

so;

Molarity = [tex]\frac{1.5 Moles}{2.0 Liters}[/tex]

According to molar concentration, the molarity of this solution is 0.75 molar.

Molar concentration is defined as a measure by which concentration of chemical substances present in a solution are determined. It is defined in particular reference to solute concentration in a solution . Most commonly used unit for molar concentration is moles/liter.

The molar concentration depends on change in volume of the solution which is mainly due to thermal expansion. Molar concentration is calculated by the formula, molar concentration=mass/ molar mass ×1/volume of solution in liters.

In terms of moles, it's formula is given as molar concentration= number of moles /volume of solution in liters.Substitution in formula gives, molarity= 1.5/2=0.75 M

Thus,  the molarity of this solution is 0.75 molar.

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#SPJ2

Answer:

yes, a compound can have more than one carbon-carbon double bond

Answer:

B. Chemical weathering

Explanation:

Erosion is the process whereby the soil and rocks are washed away by wind, water, ice or gravity.

Weathering is the process of weakening and breaking down of rocks and minerals either by non-living (abiotic) or living (biotic) factors or by both, such as temperature changes, plants and animals, acids, salts and water, etc.

From the above definitions, it can be seen that acid wearing away limestone is a rock weathering process by a non-living agent, an acid.

Option A is wrong because the process is weathering

Option B is correct because an acid is a chemical and the process involved is weathering

Option C is wrong because an acid is non-living

Option D is wrong because the process involved is weathering

Answer:

5SiO[tex]_{2}[/tex] + 2CaC[tex]_{2}[/tex] → 5Si + 2CaO + 4CO[tex]_{2}[/tex]

5   2   5   2   4  are your answers.

Answer:

Explanation: d

Answer:

B

Explanation:

Well, the cells are going through mitosis, which means that when the divide, they are going to be identical sister cells. Anyways, they are

Answer:

c Drup irrigation

Explanation:

Hope it helps you.

Plz mark as brainliest plz.

Answer:

190n

Explanation:

190 190 and because it is easy to understand if you didn't understand my answer ask any man

Answer:

The site at which the lander would have the greatest amount of gravitational potential energy is X

Explanation:

The formula for gravitational potential is given as follows;

[tex]PE_G = m \times g \times \Delta H[/tex]

Where:

g = Acceleration due to gravity

m = Mass of the lander

ΔH = Height above surface

Landing site --- Height above surface --- Acceleration due to gravity

W                        32                                    1.6

x                          16                                    3.7

Y                         35                                    1.6

Z                         12                                     3.7

Therefore, we have;

For site W

[tex]PE_G = m \times 1.6 \times 32 = 51.2 \cdot m[/tex]

For site X

[tex]PE_G = m \times 3.7 \times 16= 59.2 \cdot m[/tex]

For site Y

[tex]PE_G = m \times 1.6 \times 35 = 56 \cdot m[/tex]

For site Z

[tex]PE_G = m \times 3.7 \times 12 = 44.4 \cdot m[/tex]

Hence the site at which the lander would have the greatest amount of gravitational potential energy is X with [tex]PE_G[/tex] = 59.2·m.

Gravitational energy is the power stored in an object due to the intensity of gravity or because the article is located vertically.

The correct answer is:

The site at which the lander would have the greatest amount of gravitational potential energy is X.

The correct explanation for site X is:

The gravitational energy can be calculated as the product of mass, gravitational field and height.

[tex]{\text{PE}_{\text G}&= \text{m}\; \times\text g\times \Delta\text H[/tex]

Where,

Given,

Landing site        Height above surface              Gravity

    W                                    32                                    1.6

    X                                     16                                     3.7

    Y                                     35                                     1.6

    Z                                     12                                      3.7

We can calculate Gravitational energy for all the sites as follows:

       [tex]{\text{PE}_{\text G}&= \text{m}\; \times\ 1.6\times 32 = 51.2 \text \; \times \text {m}[/tex]

       [tex]{\text{PE}_{\text G}&= \text{m}\; \times\ 3.7\times 16 = 59.2 \text \; \times \text {m}[/tex]

       [tex]{\text{PE}_{\text G}&= \text{m}\; \times\ 1.6\times 35 = 56 \text \; \times \text {m}[/tex]

       [tex]{\text{PE}_{\text G}&= \text{m}\; \times\ 3.7 \times 12= 44.4 \text \; \times \text {m}[/tex]

Therefore, the greatest amount of gravitational energy 59.2m is present on-site X.

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