Answer:
This question is incomplete. There is no highlight in red bolded text in the question but the answer to both the independent and dependent variables will be provided and explained in details.
Independent variable: decrease in temperature
Dependent variable: lifespan of battery
Explanation:
The independent variable of an experiment refers to the variable that is changed or manipulated by the experimenter in order to bring about an outcome. In this experiment, the DECREASE IN TEMPERATURE is the independent variable because it is what is being changed to effect a response in the battery lifespan.
On the contrary, the dependent variable is the variable that responds to the manipulation of the independent variable. In other words, the dependent variable is the outcome. In this experiment, the LIFESPAN OF THE BATTERY is the dependent variable because it is what is responding to the changes made by decreasing the temperature (independent variable)
If E°(red) of a given half-cell is more negative than E°(red) for a standard hydrogen electrode, the half-cell will:
Answer:
Be the anode
Explanation:
The standard hydrogen electrode is regarded as the standard reference electrode and it has been assigned an electrode potential of 0.0V.
If any substance has an electrode potential that is more negative than hydrogen, then that half cell will function as the anode when connected to the standard hydrogen electrode.
Similarly, any substance that has a more positive electrode potential than hydrogen will serve as the cathode when its half cell is connected to the standard hydrogen electrode.
The composition of a liquid-phase reaction 2A - B was monitored spectrophotometrically. 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
1) Determine the order of the reaction. (6 pts.)
2) Find its rate constant. 19 pts.) Note: no unit is needed, just the numerical answer. Hint: convert your minutes to seconds.
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
Please Help Me Which ink spot had the most pigments? Question 3 options: A) red B) blue C) black D) green
Answer:
Black
Explanation:
A flask that weighs 345.8g is filled with 225mL of carbon tetrachloride. The weight of the flask and carbon tetrachloride is found to be 703.55g. From this information, calculate the density of carbon tetrachloride.
Answer:
Density = 1.59 g/mLExplanation:
The density of carbon tetrachloride can be found by using the formula
[tex]Density = \frac{mass}{volume} [/tex]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
[tex]Density = \frac{357.75}{225} [/tex]We have the final answer as.
Density = 1.59 g/mL
Hope this helps you
classify the organisms based on what they eat. producer consumer decomposer
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
based on the techniqes yo have learned in the organic chemistry lab how would you seperate any unreated alcohol from the ester
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.
Write the numbers in scientific notation.
291.7 = 2.917
X10%
where x =
0.0960 -
X10%
where x =
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:
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A solution is prepared at that is initially in benzoic acid , a weak acid with , and in sodium benzoate . Calculate the pH of the solution. Round your answer to decimal places.
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.
Consider a 0.238 M aqueous solution of sodium hydroxide, NaOH.
a. How many grams of NaOH are dissolved in 23.46 mL?
b. How many individual hydroxide ions (OH) are found in 23.46 mL?
c. How many moles of sulfuric acid, H2SO4, are neutralized by 23.46 mL of 0.238 M NaOH(aq)? [Hint: begin by writing a balanced equation for this neutralization reaction.]
Answer:
The correct answer is a. 0.223 grams, b. 3.36 × 10²¹ and c. 2.79 × 10⁻³ mol.
Explanation:
a. The volume of the solution given is 23.46 ml or 23.46 × 10⁻³ L, the molarity of NaOH is 0.238 M or 0.238 mol/L. Now the number of moles of NaOH will be,
Number of moles = Molarity × Volume in Liters of solution
= 0.238 mol/L × 23.46 × 10⁻³ L
= 5.5835 × 10⁻³ mol
Now the mass of NaOH will be,
= Moles × Molecular mass of NaOH
= 5.5835 × 10⁻³ mol × 39.997 g/mol
= 223.322 × 10⁻³ grams
b) The number of moles in 23.46 ml is 5.5835 × 10⁻³ mol
Now the number of hydroxide ions found will be,
= No. of moles × NA
= 5.5835 × 10⁻³ × 6.022 × 10²³
= 3.36 × 10²¹
c) The balanced chemical equation is,
2NaOH + H₂SO₄ ⇒ Na₂SO₄ + 2H₂O
The number of moles of H₂SO₄ neutralized is,
= Number of moles of NaOH taken/2
= 5.5835 × 10⁻³/2 mol
= 2.7917 × 10⁻³ mol
How many mL are in 1.000 cup?
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.
what is dual behaviour of matter
Answer:
Dual nature of matter is an important concept in JEE physics and is basically the study of different nature that a matter possesses or exhibits. ... Hence, the matter is said to possess dual nature, i.e., it has both the properties of a particle and as well as a wave.
A 1.75 gram perfect cube of wood has a side measure of 2.45 cm, what is the density of the wood?
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
(a) Atoms are very small compared to objects on the macroscopic scale. The radius of a platinum atom is 139 pm. What is this value in meters and in centimeters? ____m ____cm
( b) The mass of a single platinum atom is 3.24*1022 g. Suppose enough Pt atoms were lined up like beads on a string to span a distance of 48.1 cm (19 inches) How many atoms would be required? ___atoms
What mass in grams of Pt would be used? ___g
Could you weigh out this amount of platinum using a typical laboratory balance? Yes or no?
(c) Taking the density of platinum metal to be 21.4 g/cm^3, calculate the mass of metal needed to form a piece of Pt wire with the same length as the distance in b, but with a diameter of atoms 1.50 mm. Hint: The volume of a cylinder is π times its radius squared times its height (V = πr^2h) ___g
How many platinum atoms does this represent? ____atoms
Answer:
Kindly check explanation
Explanation:
pm = picometer
Radius of platinum atom = 139 pm
1 pm = 1 × 10^-12 m
Hence,
139 pm = 139 × 10^-12 m
1 pm = 1 × 10^-10 cm
Hence,
139 pm = 139 × 10^-10 cm
B) mass of a single platinum atom = 3.24 × 10²² g
To obtain the diameter of 1 platinum atom in cm:
139 × 10^-10 cm
Number of atoms required :
48.1 cm / 1.39 × 10^-8 cm = 34.60 × 10^8 atoms
Mass in gram of P(t) :
(3.24 × 10²²) × (34.60 × 10^8) = 112.117 × 10^(22+8)
= 112.12 × 10^30 g
C) density (d) = 21.4 g/cm^3, diameter = 1.50 mm
V = πr^2h
h = 48.1cm ; r = 1.5 / 2 = 0.75 mm = 0.075cm
Density = mass / volume
Volume = π * 0.075^2 * 48.1 = 0.8499971cm³
Mass = density × volume
Mass = 21.4g/cm³ × 0.8499971cm³
= 18.19g
Based on Figure 25-2, are red giants hotter than white dwarfs?
Answer:
No
Explanation:
A white dwarf has a higher surface temperature than a red giant.
What could be some disadvantages to this scientific method?
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:
Which pair of compounds will form a buffer in aqueous solution? a) HCN and NaCN b) HCl and NaOH c) NaCN and NaOH d) HCN and HCl e) HCl and NaCl f) NaCN and KCN
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 .
Calculate the pH of the resulting solution if 23.0 mL of 0.230 M HCl(aq) is added to 28.0 mL of 0.230 M NaOH(aq) .
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
pH = 12.35Two atoms of hydrogen combine to form a molecule
of hydrogen gas, the energy of the H2 molecule is :
(1) Greater than that of seperate atoms
(2) Equal to that of seperate atoms
(3) Lower than that of seperate atoms
(4) Some times lower and some times higher
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.
Adding charts and graphs helps a scientist
O To state the problem
O To determine trends
O To simplify results
O Both B and C
O All of the above
Answer:
b and c
Explanation:
the problem was solved through the experiment and tested
2The higher the numbers on the NFPA diamond, the more _____ the substance is.
ARare incorrect answer
BDangerous incorrect answer
CPure incorrect answer
DSafe
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.
The exhaust gas from an automobile contains 3% by volume of carbon monoxide (CO). Express this concentration in mg/m3 at 25oC and 1 atm.
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.
Cell membranes are largely hydrophobic structures. Which compound will pass through a membrane more easily, glucose or 2,4-dinitrophenol? Explain.
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.
feel free to answer any of these. i need the answer to the appropriate amount of significant figures on this pleasee
Answer:
6. (2.7*[tex]10^{5}[/tex])
8. (1.0*[tex]10^{4}[/tex])
Explanation:
sort the sequences based on the types of mutation they display
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.
Classify each substance based on the intermolecular forces present in that substance.
A. Hydrogen bonding, dipole dipole, and dispersion
B. Dipole dipole and dispersion only
C. Dispersion only
1. H2O
2. CH4
3. CO
4. CH2Cl
Answer:
H2O- Hydrogen bonding, dipole dipole, and dispersion
CH4- Dispersion only
CO- Dispersion only
CH2Cl- Dipole dipole and dispersion only
Explanation:
Dipole- dipole interactions exist only in molecules that have a dipole moment such as water and dichloromethane. Water experiences intermolecular hydrogen bonding in addition to dipole-dipole interaction and dispersion forces due to the O-H bond in the molecule.
Nonpolar compounds only have dispersion forces acting between its molecules.
Explanation:
When Dipole-dipole interactions exist only in molecules that have a dipole moment such as water and also that dichloromethane. After that Water experiences intermolecular hydrogen bonding in addition to dipole-dipole interaction and also that dispersion forces due to the O-H bond in the molecule. Thus, Nonpolar compounds only have dispersion forces acting between their molecules.Find out more information about dispersion here:
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Water vapor in the morning turns into dew on the grass.
Answer:
Dew is liquid water droplets that form on grass, spider webs, and other things in the early morning or late evening. ... That means it turns from a liquid into a gas called "water vapor." When evening comes, the warm ground continues to radiate heat into
What food color mix to make yellow?
Answer:
read and green
Explanation:
By convention, the three primary colors in additive mixing are red, green, and blue. In the absence of light of any color, the result is black. If all three primary colors of light are mixed in equal proportions, the result is neutral (gray or white). When the red and green lights mix, the result is yellow.
Answer:
ground tumeric
Explanation:
Mix 1/4 cup water and 1/2 teaspoon of ground tumeric
A textbook measures 250 mm long, 225 mm wide and 50 mm thick. What is the volume of this book in mm3? What is the volume of this book in m3?
Answer:
2.81 × 10⁶ mm³
2.81 × 10⁻³ m³
Explanation:
Step 1: Given data
Length (l): 250 mm
Width (w): 225 mm
Thickness (t): 50 mm
Step 2: Calculate the volume of the textbook
The book is a cuboid so we can find its volume (V) using the following expression.
V = l × w × t = 250 mm × 225 mm × 50 mm = 2.81 × 10⁶ mm³
Step 3: Convert the volume to cubic meters
We will use the relationship 1 m³ = 10⁹ mm³.
2.81 × 10⁶ mm³ × 1 m³ / 10⁹ mm³ = 2.81 × 10⁻³ m³
When comparing lithium, sodium, and potassium to calcium, strontium, and barium, early chemists noticed that:
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
Which statement best describes the types and locations of particles that make up the atom? 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. B. The neutral-charged neutrons, positive-charged protons, and negative-charged electrons are all found within the nucleus of the atom. C. The negative-charged electrons and positive-charged protons are found within the nucleus, and the neutral-charged neutrons orbit outside the nucleus of the atom. D. The negative-charged neutrons and positive-charged protons are found within the nucleus, and the neutral-charged electrons orbit outside the nucleus of the atom.
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.