Which list includes all the steps of a descriptive investigation? A. is asking questions, making observations, collecting data, comparing, and forming a conclusion B. Asking questions, making observations, experimenting, analyzing data, and forming a conclusion C. Asking questions, making observations, experimenting, and overcoming limitations D. Asking questions, making observations, collecting data, and forming a conclusion

Answer:

107.55 J, 88.67 cal

Explanation:

1 Joule = 0.239 Calories

450 cal x 0.239 = 107.55 J

3.5 x 106 = 371

371 J = 371 x 0.239 cal

371 J = 88.67 cal

Answer:

Explanation:

Since the mass of NaCl and it's volume has been given we can find the molarity by using the formula

where

C is the molarity

m is the mass

M is the molar mass

v is the volume

From the question

v = 0.5 L

m = 205 g

We must first find the molar mass and then substitute the values into the above formula

M( Na) = 23 , M( Cl) = 35.5

Molar mass of NaCl = 23 + 35.5 =

58.5 g/mol

So the molarity of NaCl is

[tex]C = \frac{205}{0.5 \times 58.5} \\ C = \frac{205}{29.25} [/tex]

C = 7.00854

We have the final answer as

Hope this helps you

Answer: 1×10^11

Explanation:

concept to know: scientific notation must be written in the form of a × 10^b

where 0<a<10.

100 billion= 100,000,000,000

there are 11 zeros after 1

1 × 10^11

Hope this helps!! :)

Answer: 2.652882206 but it depends on how you round it so I would say 2.65 or 2.7 g/mL

Explanation: Density is mass divided by volume

Explanation:

1 mile = 1.61 km and 1 km = 1000 m

The speed of light is [tex]3\times 10^8\ m/s[/tex]. We need to convert it into miles per hour.

1 m = (1/1000) km

[tex]3\times 10^8\ m=\dfrac{3\times 10^8}{1000}\\\\=3\times 10^5\ km[/tex]

1 km = (1/1.61) miles

[tex]3\times 10^5\ km =\dfrac{3\times 10^5}{1.61}\\\\=1.86\times 10^5\ \text{miles}[/tex]

So, [tex]v=1.86\times 10^5\ \text{miles/s}[/tex]

Hence, this is the required solution.

Answer:

False

Explanation:

Hello,

In this case, it is possible to substantiate that the statement is false, since the entropy of sucrose is greater than the entropy of ribose due to the fact that molar mass of the sucrose (342 g/mol) is greater than the molar mass of ribose (150 g/mol) and the general rule states that the greater the molar mass the greater the entropy.

Best regards.

Answer:

[tex][base]=0.28M[/tex]

Explanation:

Hello,

In this case, by using the Henderson-Hasselbach equation one can compute the concentration of acetate, which acts as the base, as shown below:

[tex]pH=pKa+log(\frac{[base]}{[acid]} )\\\\\frac{[base]}{[acid]}=10^{pH-pKa}\\\\\frac{[base]}{[acid]}=10^{4.9-4.76}\\\\\frac{[base]}{[acid]}=1.38\\\\[/tex]

[tex][base]=1.38[acid]=1.38*0.20M=0.28M[/tex]

Regards.

Answer:

London forces only

Explanation:

Dimethyl ether is a nonpolar organic compound. Remember that for nonpolar organic substances, London forces are the primary intermolecular forces present.

Since dimethyl ether is a nonpolar organic compound, then it has London forces as its major intermolecular force. Intermolecular forces hold molecules of a substance together in a given state of matter.

Explanation:

for immiscible liquids it is quite easy to separate and the separating funnel can be used but for miscible liquid they form a single entity and separating them is quite impossible if the differences in temperature is not considered,so in distillation the one with lower boiling point evaporates out living behind the one with high boiling point

Answer:

Electrons occupy orbitals with the lowest energy first.

Explanation:

The Aufbau Principle states that electrons will fill the atomic orbitals with the lowest energy levels first, before occupying others with higher energy levels.

For example, electrons will fill the 1s orbital before filling the 2s orbital.

Answer:

It is Filled sublevels are more stable than partially filled sublevels.

Explanation:

Just took the test and this was right.

Answer:

Explanation:

The density of a substance can be found by using the formula

[tex]Density = \frac{mass}{volume} [/tex]

From the question

mass = 52 g

volume = 26 mL

Substitute the values into the above formula and solve for the density

That's

[tex]Density = \frac{52}{26} [/tex]

We have the final answer as

Hope this helps you

Answer:

Explanation:

Hello,

In this case, considering the given specific gravity we are to compute the density of the 64% HNO3 solution:

[tex]\rho=1.24*1g/mL=1.24g/mL[/tex]

In such a way, since the given solution of nitric acid is 64 % by mass, we've got:

[tex]\frac{64gHNO_3}{100g\ solution}[/tex]

Thus, by using the previously computed density and the molar mass of HA (90.2 g/mol) we can compute the required molar concentration as follows:

[tex]M=\frac{(100g-64g)HA}{100g\ solution}*\frac{1.24g\ solution }{1mL \ solution}*\frac{1000mL\ solution}{1L\ solution}*\frac{1molHA}{90.2gHA} \\\\M=4.95M[/tex]

Regards.

Answer:

Sebacic acid is a naturally occurring dicarboxylic acid with the formula (CH2)8(CO2H)2. It is a white flake or powdered solid. Sebaceus is Latin for tallow candle, sebum is Latin for tallow, and refers to its use in the manufacture of candles.

Explanation:

pls mark as brainliest!!!!!

Answer:

two of them are chemical changes

Explanation:

1.) the copper roof turns green over time: it forms a new substance which is the green deposit known as verdigris .

2.) baking soda is dissolved in vinegar and bubbles form: it forms a new substance which is carbon dioxide gas.

   I hope it helps:)

Answer:

229%

Explanation:

The equation of the reaction is;

4Al(s) + 3O2(g) ----> 2Al2O3(s)

We must first determine the limiting reactant;

Number of moles of Al2O3 produced = mass/molar mass = 72.4g/101.96 g/mol = 0.71 moles

For Al

Number of moles reacted = mass/molar mass = 49.2g/27 g/mol = 1.8 moles

If 4 moles of Al yields 0.71 moles of Al2O3

1.8 moles of Al will yield 1.8 × 0.71/4 = 0.32 moles of Al2O3

For O2

Number of moles reacted = mass/molar mass = 42.6g/32g/mol = 1.33 moles

If 3 moles of O2 yields 0.71 moles of Al2O3

1.33 moles of O2 will yield 1.33 × 0.71/3 = 0.31 moles of Al2O3

Oxygen is the limiting reactant.

% yield = actual yield/ theoretical yield × 100/1

% yield = 0.71 moles/0.31 moles × 100

% yield = 229%

Answer:

Keep a close eye on her in case she starts giving birth to the next pup at the same time. A greenish/brown discharge may suggest a placenta has separated. If you see this, a puppy should be born within the next 2-4 hours.

Liters and millilitres are the most common units of volume.

The volume equal to a gallon of gasoline is 3785 m L which is equal to 3.785 L.

The volume equal to pint of milk is 473...

A a cup of water is 0.24 L

Answer:

6.2 × 10^-2

Explanation:

Given the reaction:

------------2N2O(g) N2H4(g) <---> 3N2(g) 2H2O(g)

Initial: N2O = 0.1, N2H4 = 0.25-- 0 - - - - - 0

Then: N20 = -2x, N2H4= - x - - - +3x, +2x

Equ : 0.1 - 2x ; 0.25 - x ; +3x ; +2x

At equilibrium :

Add both:

N2O = 0.1 - 2x ;

N2H4 = 0.25 - x;

3N2 = 3x

2H2O = 2x

Moles of N2O at equilibrium = 0.059

Then;

0.1 - 2x = 0.059

-2x = 0.059 - 0.1

-2x = - 0.041

x = 0.041 / 2

x = 0.0205

Moles of N2 present at equilibrium ;

3N2 = 3x

3N2 = 3(0.0205)

= 0.0615

= 0.062 = 6.2 × 10^-2

Answer:

115g

Explanation:

100*8=800

800+150+200=1150

1150/10=115

Answer:

yes it is as it has a chemical formula which cannot be changed

Answer:

92.72 kJ

Explanation:

2 N₂ (g) + O₂ (g) —-> 2 N₂O

According to question , one mole of N₂O requires 163.2 kJ of heat

Molecular weight of N₂O = 44 gm

25 g  N₂O = 25 / 44 mole

25 / 44 mole will require 163.2 x 25 / 44 kJ

= 92.72 kJ

Answer:

i try to solve it for you, and i aplode a similer question for you

Explanation:

Answer:

Explanation:

The pH of the solution can be found by using the formula

pH = - log [H+]

From the question

[H+] = 10^-5 M

Substitute the value into the above formula and solve for the pH

That's

[tex]pH = - log( {10}^{ - 5} ) [/tex]

We have the final answer as

pH = 5

Hope this helps you

The question is missing parts. The complete question is as follows.

Consider the two gaseous equilibria involving SO2 and the corresponding equilibrium constants at 298K:

[tex]SO_{2}_{(g)} + \frac{1}{2}O_{2}[/tex] ⇔ [tex]SO_{3}_{(g)}[/tex]; [tex]K_{1}[/tex]

[tex]2SO_{3}_{(g)}[/tex] ⇔ [tex]2SO_{2}_{(g)}+O_{2}_{(g)}; K_{2}[/tex]

The values of the equilibrium constants are related by:

a) [tex]K_{1}[/tex] = [tex]K_{2}[/tex]

b) [tex]K_{2} = K_{1}^{2}[/tex]

c) [tex]K_{2} = \frac{1}{K_{1}^{2}}[/tex]

d) [tex]K_{2}=\frac{1}{K_{1}}[/tex]

Answer: c) [tex]K_{2} = \frac{1}{K_{1}^{2}}[/tex]

Explanation: Equilibrium constant is a value in which the rate of the reaction going towards the right is the same rate as the reaction going towards the left. It is represented by letter K and is calculated as:

[tex]K=\frac{[products]^{n}}{[reagents]^{m}}[/tex]

The concentration of each product divided by the concentration of each reagent. The indices, m and n, represent the coefficient of each product and each reagent.

The equilibrium constants of each reaction are:

[tex]SO_{2}_{(g)} + \frac{1}{2}O_{2}[/tex] ⇔ [tex]SO_{3}_{(g)}[/tex]

[tex]K_{1}=\frac{[SO_{3}]}{[SO_{2}][O_{2}]^{1/2}}[/tex]

[tex]2SO_{3}_{(g)}[/tex] ⇔ [tex]2SO_{2}_{(g)}+O_{2}_{(g)}[/tex]

[tex]K_{2}=\frac{[SO_{2}]^{2}[O_{2}]}{[SO_{3}]^{2}}[/tex]

Now, analysing each constant, it is easy to see that [tex]K_{1}[/tex] is the inverse of [tex]K_{2}[/tex].

If you doubled the first reaction, it will have the same coefficients of the second reaction. Since coefficients are "transformed" in power for the constant, the relationship is:

[tex]K_{2}=\frac{1}{K_{1}^{2}}[/tex]

Answer:

[H₂SO₄] = 4.56 M

Explanation:

35.2 % by mass of H₂SO₄ means that in 100 g of solution, we have 35.2 grams of solute.

We convert the mass of solute to moles.

35.2 g / 98 g/mol = 0.359 moles

These moles are contained in 100 g of solution, so we use density to determine the volume.

1.27 g/mL = 100 g / volume

Volume = 100 g / 1.27 g/mL = 78.74 mL

Molarity is mmol /mL (either we can say, moles in 1L of solution).

We convert the moles to mmoles → 0.359 mol . 1000 = 359 mmoles

M = 359 mmoles/74.74 mL = 4.56 M

Answer:

The Earth is divided into two halves by the prime meridian, forming two half spheres divided vertically. The Earth is also divided into two halves by the equator, creating two half spheres divided horizontally.

Explanation:

I took it on edge ( :

Answer:1.6989

Explanation:

The pH of the solution prepared by mixing NaOH and [tex]\rm HNO_3[/tex] has been 1.69.

The moles of NaOH can be given by:

Moles = Molarity × Volume (L)

Moles of NaOH = 0.002 mol

Moles of [tex]\rm HNO_3[/tex] = 0.003 mol

Since,  [tex]\rm HNO_3[/tex] has been remaining in the solution after neutralization, the moles of [tex]\rm HNO_3[/tex] has been :

[tex]\rm HNO_3[/tex] = 0.003 - 0.002 mol

[tex]\rm HNO_3[/tex] = 0.001 mol.

The moles of [tex]\rm HNO_3[/tex] has been equivalent to the moles of hydrogen ion.

The hydrogen ion has been 0.001 mol.

The concentration of Hydrogen ions can be given by:

Hydrogen ion concentration = [tex]\rm \dfrac{Moles}{Volume(L)}[/tex]

Hydrogen ion concentration = [tex]\rm \dfrac{0.001}{0.03\;+\;0.02}[/tex]

Hydrogen ion concentration = 0.02 M.

pH can be defined as the negative log of the hydrogen ion concentration.

pH = - log ([tex]\rm H^+[/tex])

pH = - log (0.02)

pH = 1.69

The pH of the solution prepared by mixing NaOH and [tex]\rm HNO_3[/tex] has been 1.69.

For more information about the pH of the solution, refer to the link:

https://brainly.com/question/4975103

Answer:

The rate of reaction is unchanged

Explanation:

The rate of reaction of tertiary alkyl halides with a nucleophile is independent of the nucleopohile concentration but depends only on the initial concentration of the alkyl halide since tertiary alkyl halides reacts via SN1 mechanism.

The nucleophile concentration does not come into the rate equation for the reaction hence any change in its concentration is inconsequential in determining the overall rate of reaction, hence the rate of reaction is unchanged when the nucleophile concentration is halved.

Answer:

A

Explanation:

The measurement represents the largest quantity among the given options is 47.3 mg Hence, Option (A) is correct.

An arithmetical multiplier for converting a quantity expressed in one set of units into an equivalent expressed in another.

Therefore comparing all the four options it can be concluded that,The measurement represents the largest quantity among the given options is 47.3 mg Hence, Option (A) is correct.

Learn more about measurement here ;

https://brainly.com/question/18147632

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