What does science mean to you

Answer:

1) The order of the reaction is of FIRST ORDER

2)   Rate constant k = 5.667 × 10 ⁻⁴

Explanation:

From the given information:

The composition of a liquid-phase reaction 2A - B was monitored spectrophotometrically.

liquid-phase reaction 2A - B signifies that the reaction is of FIRST ORDER where the rate of this reaction is directly proportional to the concentration of A.

The following data was obtained:

t/min                    0         10         20          30             40          ∞

conc B/(mol/L)    0       0.089    0.153     0.200       0.230    0.312

For  a first order reaction:

[tex]K = \dfrac{1}{t} \ In ( \dfrac{C_{\infty} - C_o}{C_{\infty} - C_t})[/tex]

where :

K = proportionality  constant or the rate constant for the specific reaction rate

t = time of reaction

[tex]C_o[/tex] = initial concentration at time t

[tex]C _{\infty}[/tex] = final concentration at time t

[tex]C_t[/tex] = concentration at time t

To start with the value of t when t = 10 mins

[tex]K_1 = \dfrac{1}{10} \ In ( \dfrac{0.312 - 0}{0.312 - 0.089})[/tex]

[tex]K_1 = \dfrac{1}{10} \ In ( \dfrac{0.312 }{0.223})[/tex]

[tex]K_1 =0.03358 \ min^{-1}[/tex]

[tex]K_1 \simeq 0.034 \ min^{-1}[/tex]

When t = 20

[tex]K_2= \dfrac{1}{20} \ In ( \dfrac{0.312 - 0}{0.312 - 0.153})[/tex]

[tex]K_2= 0.05 \times \ In ( 1.9623)[/tex]

[tex]K_2=0.03371 \ min^{-1}[/tex]

[tex]K_2 \simeq 0.034 \ min^{-1}[/tex]

When t = 30

[tex]K_3= \dfrac{1}{30} \ In ( \dfrac{0.312 - 0}{0.312 - 0.200})[/tex]

[tex]K_3= 0.0333 \times \ In ( \dfrac{0.312}{0.112})[/tex]

[tex]K_3= 0.0333 \times \ 1.0245[/tex]

[tex]K_3 = 0.03412 \ min^{-1}[/tex]

[tex]K_3 = 0.034 \ min^{-1}[/tex]

When t = 40

[tex]K_4= \dfrac{1}{40} \ In ( \dfrac{0.312 - 0}{0.312 - 0.230})[/tex]

[tex]K_4=0.025 \times \ In ( \dfrac{0.312}{0.082})[/tex]

[tex]K_4=0.025 \times \ In ( 3.8048)[/tex]

[tex]K_4=0.03340 \ min^{-1}[/tex]

We can see that at the different time rates, the rate constant of [tex]k_1, k_2, k_3, and k_4[/tex] all have similar constant values

As such :

Rate constant k = 0.034 min⁻¹

Converting it to seconds ; we have :

60 seconds = 1 min

∴

0.034 min⁻¹ =(0.034/60) seconds

= 5.667 × 10 ⁻⁴ seconds

Rate constant k = 5.667 × 10 ⁻⁴

Answer:

2,4-dinitrophenol

Explanation:

A hydrophobic molecule does not dissolve nor mix with water. The cell membranes are made up of hydrophobic lipids. Hence, hydrophobic molecules easily pass through the cell membrane.

Glucose is partly hydrophilic hence it is transported across the cell membrane by special proteins. However, 2,4-dinitrophenol is a hydrophobic molecule thus it is easily transported across the cell membrane.

Answer:

[tex]24540\frac{mg}{m^3}[/tex]

Explanation:

Hello,

In this case, since the 3% by volume is represented as:

[tex]\frac{3L\ CO}{L\ gas}[/tex]

By using the ideal gas equation we compute the density of CO:

[tex]\rho =\frac{MP}{RT} =\frac{28g/mol*1atm}{0.082\frac{atm*L}{mol*K}*298K}= 0.818g/L[/tex]

Then we apply the conversion factors as follows:

[tex]=\frac{3L\ CO}{100L\ gas}*\frac{0.818g\ CO}{1L\ CO} *\frac{1000mg\ CO}{1g\ CO} *\frac{1000L\ gas}{1m^3\ gas} \\\\=24540\frac{mg}{m^3}[/tex]

Regards.

Answer:

Black

Explanation:

Answer:

pH = 12.35

Explanation:

The HCl reacts with NaOH, thus:

HCl + NaOH → NaCl + H₂O

1 mole of HCl reacts per mole of NaOH

To know the pH we must know the moles of NaOH and the moles of HCl that reacts

Moles NaOH and HCl

NaOH: 0.0280L * (0.230mol / L) = 6.44x10⁻³ moles

HCl: 0.0230L * (0.230mol / L) = 5.29x10⁻³

As moles NaOH > Moles HCl, the moles that remains of NaOH are:

Moles NaOH = 6.44x10⁻³ - 5.29x10⁻³ = 1.15x10⁻³ moles NaOH = Moles OH⁻

In 23.0mL + 28.0mL = 51.0mL = 0.0510L:

1.15x10⁻³ moles OH⁻ / 0.0510L =

0.0225M OH⁻

pOH = -log [OH⁻]

pOH = 1.647

And pH = 14 - pOH

Answer:

The reason for this is that putting out the fires only postpones the fire outbreak to a later date, and there is the fear of the fire outbreak being more sever when it actually comes.

When wildfires burn, they clean up the forest off dead trees and falling logs. Also dried leaves and twigs and unnecessarily dense vegetation is cleared up by the fire. These materials are the main fuel of these wildfires. Putting out these fires, especially those that start naturally means that these fuel that should be cleaned up are allowed to accumulate so that when the fire actually happens, it does so with an unnatural intensity. Also, when fire burns, the ashes that are left act as nutrition for the forest, and the forest is allowed to regrow; reborn from the ashes. The only cases that might need human intervention is when the fire is human caused or due to human activities. Natural causes of fire can be due to a very high temperature, lightning striking a tree, etc.

Answer:

17.5609g

Explanation:

According to the question, a sample of mass 6.814 grams is added to another sample weighing 0.08753 grams. That is weight of sample 1 + weight of sample 2;

6.814 + 0.08753 = 6.90153grams

Next, the subsequent mixture is then divided into exactly 3 equal parts i.e. 6.90153grams divided by 3

= 6.90153/3

= 2.30051grams.

One of the equal parts is 2.30051grams, which is then multiplied by 7.6335 times I.e. 2.30051 × 7.6335 = 17.5609grams

Therefore, the final mass is 17.5609grams

Answer:

Nothing has full knowledge of the world.

Senses can deceive us - science only provides us with an incomplete picture of the world.

Scientists can never be completely unbiased.

Science isn't free from error.

No way of knowing what is real - some things could be illusions

Explanation:

Answer:

b and c

Explanation:

the problem was solved through the experiment and tested

Answer:

Explanation:

Lithium, Potassium and Sodium follow each other in that order when it comes to reactivity.

Succinctly put, Lithium is the most reactive. Potassium is more reactive and Sodium is the least reactive.

Also, for Calcium, Strontium and Barium. It is the least reactive in this order.

Strontium, Barium, Calcium

That is, Strontium is more reactive than Barium, which is more reactive than Calcium. Calcium is the least reactive of the 3

Answer:

the answer is B the particles are not chemically bonded, they can only be combined in a certain set ratios

Explanation:

Answer:

236588

Explanation:

1000 x 237 for an approx. amount

Answer:

236.588 mL in 1 cup.

Explanation:

For this problem, you must know that 1 cup is equal to 8 ounces and that 1 ounce is 29.5735 mL.  Using this information, let' perform the conversion.

1 cup * ( 8 oz / 1 cup ) * ( 29.5735 mL / 1 oz) == ? mL

( 1 cup * 8 oz * 29.5735 mL ) / ( 1 cup * 1 oz) == ? mL

236.588 mL == ? mL

Hence, there are 236.588 mL in 1 cup.

Cheers.

Answer:

Fractional distillation and HP-LC

Explanation:

This is a technique useful for analytes with close boiling points. Any alcohol-ester azotopes can be further refined using high-performance liquid chromatography (HP-LC) column.

Answer:

No

Explanation:

A white dwarf has a higher surface temperature than a red giant.

Answer:

lower than the separate atoms. Because an electron in this molecular orbital is strongly attracted to both nuclei, the electron is more stable (at lower energy) than it is in the 1s orbital of the hydrogen atom. Because it concentrates electron density between the nuclei, the bonding molecular orbital holds the atoms together in a covalent bond.

Answer:

6. (2.7*[tex]10^{5}[/tex])

8. (1.0*[tex]10^{4}[/tex])

Explanation:

Answer:

0.119 g/cm³

Explanation:

Step 1: Given data

Mass of the cube (m): 1.75 g

Side measure (l): 2.45 cm

Step 2: Calculate the volume of the cube

We will use the following expression.

V = l³

V = (2.45 cm)³

V = 14.7 cm³

Step 3: Calculate the density (ρ) of the cube

The density of the cube is equal to its mass divided by its volume.

ρ = m/V

ρ = 1.75 g/14.7 cm³

ρ = 0.119 g/cm³

Answer:

A. The neutral-charged neutrons and positive-charged protons are found within the nucleus, and the negative-charged electrons orbit outside the nucleus of the atom.

Explanation:

An atom basically consists of three sub atomic particles. They are; Neutrons, Electrons and Protons.

The Electrons are negatively charged and can be found outside the nucleus of the atom,

The Protons are positively charged and can be found in the nucleus of an atom.

The Neutrons are neutral in terms of charged and can be found in the nucleus along with the protons.

The option that is correct is;

A. The neutral-charged neutrons and positive-charged protons are found within the nucleus, and the negative-charged electrons orbit outside the nucleus of the atom.

Answer:

Explanation:

The density of carbon tetrachloride can be found by using the formula

From the question

Volume = 225 mL

To find the mass of carbon tetrachloride in the flask subtract the mass of the flask from the total mass of the flask and carbon tetrachloride

That's

mass of carbon tetrachloride =

703.55 - 345.8

= 357.75 g

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

That's

We have the final answer as.

Density = 1.59 g/mL

Hope this helps you

Answer:

a) HCN and NaCN

Explanation:

Buffer solution is made by mixing either a weak base and its salt like ammonia and ammonium chloride or weak acid and its salt like HCN and its salt NaCN or acetic acid and sodium acetate .

In the given option , all of the rest of option has either strong acid or strong base or both  . In the last option both are salt so it can not form buffer solution .

It is capable of keeping the pH of the solution constant .

Answer:

There are three types of DNA Mutations: base substitutions, deletions and insertions. Single base substitutions are called point mutations, recall the point mutation Glu -----> Val which causes sickle-cell disease. Point mutations are the most common type of mutation and there are two types.

The correct answer is B. Dangerous

Explanation:

The NFPA diamond is used to show how safe or dangerous a substance or material is based on four main categories: Health (blue), Flammability (red), Instability (yellow), special hazards (white). Moreover, the three first hazards are expressed using numbers from 0 to 4, in which 0 means no hazard while 4 is the most dangerous category. For example, in the health square finding 0 means the substance represents no hazard for health, while 4 means the substance is lethal. This means the higher the number in this diamond, the most dangerous the substance is.

Explanation:

The amount of daylight hours affects a chicken's reproductive cycle. Hens will begin laying when the amount of daylight reaches 14 hours per day during early spring. Maximum egg laying will occur when the day length reaches 16 hours per day

Answer:

1.52 g/mL

Explanation:

The formula for finding the density of an object is d = m/v, or density = mass divided by volume.

Therefore, we can input the two values and solve for d.

d = 220/145

d = 44/29

d ≈ 1.52 g/mL

Answer:

[tex]pH=4.1[/tex]

Explanation:

Hello,

In this case, for a concentration of 0.42 M of benzoic acid whose Ka is 6.3x10⁻⁵ in 0.33 M sodium benzoate, we use the Henderson-Hasselbach equation to compute the required pH:

[tex]pH=pKa+log(\frac{[base]}{[acid]} )[/tex]

Whereas the concentration of the base is 0.33 M and the concentration of the acid is 0.42 M, thereby, we obtain:

[tex]pH=-log(Ka)+log(\frac{[base]}{[acid]} )\\\\pH=-log(6.3x10^{-5})+log(\frac{0.33M}{0.42M} )\\\\pH=4.1[/tex]

Regards.

The numbers in scientific notation are 291.7 = 2.917 × 10₂ and 0.0960 = 9.60 × 10⁻².

Scientific notation is commonly used in scientific and mathematical calculations, as well as when dealing with very large or very small numbers. It allows for a more compact and manageable representation of these numbers.

To write the numbers in scientific notation, we need to express them in the form of "a × 10^b," where "a" is a number between 1 and 10, and "b" is an integer.

For the number 291.7, write it in scientific notation as:

291.7 = 2.917 × 10²

For the number 0.0960, write it in scientific notation as:

0.0960 = 9.60 × 10⁻²

To learn more about scientific notation, follow the link:

https://brainly.com/question/19625319

#SPJ6

Lowest - Producer - plants (mostly)

They get food by converting sunlight into nutrients

Middle - Consumer - example animals

They eat other living things such as plants or other animals for their nutrients

Top - Decomposer - bacteria/microorganisms

They decompose dead body

sorry if im wrong

Answer:

through Rhizobium bacteria

Answer:

20g gas contains and this so allow in tha 36G in per laar

Explanation: