Answer:
the correct answer is 23:19
Calculate the pressure kPa of 0.421 mole of helium gas at 254 degree celsius when it occupies a volume of 3.32 L.
Cells can regulate different processes in two ways. They can turn on and off the genes that make enzymes, or they can
A)
increase the activation energy of a reaction.
B)
increase the amount of energy needed to carry out the preferred process.
C)
regulate the enzymes that are already made.
D)
decrease the amount of energy needed to carry out the preferred process.
Answer:
im pretty sure its d
Explanation:
Calculate the volume of this regular solid.
What is the volume of the rectangular prism?
1
6 cm
5 cm
9 cm
what is the digiMelt Start Temp and the digiMelt Stop Temp for Formic Acid Acetic Acid Propionic Acid
Explanation:
Melting is defined as the physical process where a solid state of a substance converts into its liquid state. No change of chemical composition takes place, just the physical state of water is changing.
[tex]\text{Solid}\rightleftharpoons \text{Liquid}[/tex]
There are given carboxylic acids. The melting point of these acids increases to its second group member which is ethanoic acid due to prevalent hydrogen bonding. To break this bonding, a high amount of heat needs to be applied.
But as we move forward, the melting point decreases sharply as an increase in the number of carbon atoms decreases the hydrogen bonding.
Melting point of Formic Acid = [tex]8.3^oC[/tex]
Melting point of Acetic Acid = [tex]16.6^oC[/tex]
Melting point of Propionic Acid = [tex]-21^oC[/tex]
Explain why the buffering action of these chemical reactions is limited by the present day rate of change for atmospheric CO2 concentration
Answer:
Due to increase in carbondioxide gas.
Explanation:
The buffering action of these chemical reactions is limited by the present day rate of change for atmospheric carbondioxide concentration because the the rate of atmospheric carbondioxide rises as compared to ancient atmospheric carbondioxide gas. Due to increase of human activities, the concentration of carbondioxide gas increases in the atmosphere which limits the buffering action of these chemical reactions so we can say that carbondioxide gas is responsible for its limited action.
is kcn a ternary ionic compound?
Answer:
The given molecule is KCN.
Is it a ternary ionic compound?
Explanation:
A ternary ionic compound is one that consists of at least one polyatomic ion/radical.
In the given molecule,
the ions present are:
K+ and CN-.
CN- is a polyatomic acidic radical.
Hence, the given molecule is ternary ionic compound.
Question: What happens with the electrons between two atoms in a polar covalent bond?
a) Electrons are equally shared
b) Electrons are transferred
c) Electrons are unequally shared
d) Electrons become mobile in a ‘sea of electrons’
Answer:
c) Electrons are unequally shared
In the titration of a solution of Sodium hydroxide, an acid titrant was prepared by diluting 125.0 mL of 10.00 mol/L Nitric acid into enough distilled water to make 500.0 mL of solution. 30.0 mL of the base was measured, and in the titration, 16.74 mL of the acid titrant was needed to neutralize. Determine the concentration of the Sodium hydroxide.
Answer:
1.395M NaOH
Explanation:
Sodium hydroxide, NaOH, reacts with nitric acid, HNO3, as follows:
NaOH + HNO3 → NaNO3 + H2O
Where 1mol of NaOH reacts with 1mol of HNO3
To solve this question we must find the concentration of the titrant. With the concentration and the needed acid we can find the moles of HNO3 added = moles NaOH in the solution. With the moles of NaOH and its volume we can find its concentration as follows:
HNO3 concentration:
10.00mol/L HNO3 * (125.0mL/500.0mL) = 2.500M HNO3
Moles HNO3 = Moles NaOH:
16.74mL = 0.01674L*(2.500mol/L) = 0.04185 moles HNO3 = Moles NaOH
Concentration NaOH:
0.04185 moles / 0.0300L =
1.395M NaOH
PLS I REALLY NEED HELP DUE FODAY
For the reaction of hydrogen gas with iodine gas to make hydrogen iodide gas, H2 + 12 → 2HI, you have the following concentrations at equilibrium: [HQ] = 4.5647 x 10-3 M, [12] = 7.378 x 10-4 [HI] = 1.3544 x 10-2 M. M, and What is the equilibrium constant?
0.4997
0.54
46.33
54.47
Answer: The equilibrium constant for the reaction is 54.47
Explanation:
The equilibrium constant is defined as the ratio of the concentration of products to the concentration of reactants raised to the power of the stoichiometric coefficient of each. It is represented by the term [tex]K_{eq}[/tex]
The given chemical equation follows:
[tex]H_2+I_2\rightleftharpoons 2HI[/tex]
The expression for equilibrium constant will be:
[tex]K_{eq}=\frac{[HI]^2}{[H_2][I_2]}[/tex]
We are given:
[tex][HI]_{eq}=1.3544\times 10^{-2}M[/tex]
[tex][H_2]_{eq}=4.5647\times 10^{-3}M[/tex]
[tex][I_2]_{eq}=7.378\times 10^{-4}M[/tex]
Putting values in above expression, we get:
[tex]K_{eq}=\frac{(1.3544\times 10^{-2})^2}{(4.5647\times 10^{-3})(7.378\times 10^{-4})}\\\\K_{eq}=54.47[/tex]
Hence, the equilibrium constant for the reaction is 54.47
How many centimeters are in 5 miles? Hint: 1 miles = 5280 feet
Plutonium-196 has an atomic number of 78. It has ____ neutrons.
Answer:
118 neutrons
Explanation:
There are three subatomic particles in an atom namely: electron, neutron and proton. The mass number of an atom is calculated by adding the proton no. (atomic mass) + neutron no.
That is;
Mass no. = proton no. + neutron no.
This means that to obtain the neutron no. in the atom of an element, we subtract the no of protons or atomic mass from the mass number.
According to this question, Plutonium-196 is said to have an atomic number of 78. The mass no. is 196, hence, the number of neutrons is:
196 - 78
= 118 neutrons.
Identifying Conditions for Natural Selectlon
What are the conditions required for natural selection? Check all that apply.
Answer:
reproduction, variation in fitness, heredity, variation in individual characters
1. A light bulb is filled with 3.54 g of argon at 25 C and 725 mmHg. What is
the volume of this gas?
Answer: The volume of given gas is 2.27 L.
Explanation:
Given: Mass = 3.54 g
Temperature = [tex]25^{o}C[/tex] = (25 + 273) K = 298 K
Pressure = 725 mm Hg (1 mm Hg = 0.00131579) = 0.95 atm
As moles is the mass of substance divided by its molar mass.
So, moles of argon (molar mass = 40 g/mol) is as follows.
[tex]Moles = \frac{mass}{molar mass}\\= \frac{3.54 g}{40 g/mol}\\= 0.0885 mol[/tex]
Formula used to calculate the volume of given gas is as follows.
PV = nRT
where,
P = pressure
V = volume
n = no. of moles
R = gas constant = 0.0821 L atm/mol K
T = temperature
Substitute the values into above formula as follows.
[tex]PV = nRT\\0.95 atm \times V = 0.0885 mol \times 0.0821 L atm/mol K \times 298 K\\V = 2.27 L[/tex]
Thus, we can conclude that the volume of given gas is 2.27 L.
How much heat energy is released if 24.3 g of gold is cooled from 2580.0°C to room temperature (20.0°C)?
Answer:
-8024.832 J
Explanation:
The amount of heat energy lost or released, Q, can be calculated thus;
Q = m × c × ∆T
Where;
Q = amount of heat lost (J)
m = mass of substance (g)
c = specific heat capacity (J/g°C)
∆T = change in temperature (°C)
According to this question,
Q = ?
m = 24.3 g
c of Gold = 0.129 J/g°C
∆T = 20°C - 2580.0°C = -2560°C
Using Q = m × c × ∆T
Q = 24.3 × 0.129 × -2560°C
Q = -8024.832 J
This means that 8024.832 J of energy is lost or released.
Which element has the highest first ionization energy?
a. phosphorus
b. aluminum
c. sodium
d. calcium
Answer:
A) Phosphorus
Explanation:
Look At Question 5) On The Answer Key
The element phosphorus has the greatest first ionization energy.
What is the first ionization energy?The first ionization energy of an element is the energy that is required to remove an electron from the outermost shell of an atom of the element.
We know that ionization energy decreases down the group but increases across the period thus the element phosphorus has the greatest first ionization energy.
Learn more about ionization energy:https://brainly.com/question/16243729?
#SPJ6
How many moles of H2O
moles of H2O are needed to produce 55.7 moles of H2?
Answer: 55.7 moles of [tex]H_2O[/tex] are needed to produce the given amount of [tex]H_2[/tex]
Explanation:
The number of moles is defined as the ratio of the mass of a substance to its molar mass.
The equation used is:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)
Given values:
Moles of [tex]H_2[/tex] = 55.7 moles
The chemical equation for the decomposition of water follows:
[tex]2H_2O\rightarrow 2H_2+O_2[/tex]
By the stoichiometry of the reaction:
If 2 moles of hydrogen gas is produced from 2 moles of water
So, 55.7 moles of hydrogen gas will be produced by = [tex]\frac{2}{2}\times 55.7=55.7mol[/tex] of water
Hence, 55.7 moles of [tex]H_2O[/tex] are needed to produce the given amount of [tex]H_2[/tex]
Taking into account the reaction stoichiometry,
Reaction stoichiometryIn first place, the balanced reaction is:
2 H₂O → 2 H₂ + O₂
By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:
H₂O: 2 molesH₂: 2 molesO₂: 1 moleMoles of H₂O requiredThe following rule of three can be applied: if by reaction stoichiometry 2 moles of H₂ are produced from 2 moles of H₂O, 55.7 moles of H₂ are produced from how many moles of H₂O?
[tex]moles of H_{2} O=\frac{55.7 moles of H_{2}x 2 moles of H_{2} O}{2 moles of H_{2}}[/tex]
moles of H₂O= 55.7 moles
Finally, 55.7 moles of H₂O is requiredto produce 55.7 moles of H₂.
Learn more about the reaction stoichiometry:
brainly.com/question/24741074
brainly.com/question/24653699
What is20 grams of HNO^3
63.01284*20=1260.568
Explanation:
Here are the answers for both of the question you send :)
hope this helps you to understand:)
GIVE BRAINLIEST
Which property of water helps it maintain a relatively stable temperature?
The property of water that helps it maintain a relatively stable temperature is the presence of hydrogen bonds.
The properties of waterWater is an odourless, tasteless and colourless compound that is made up of hydrogen and oxygen atoms.
The properties of water include the following:
it is a polar solvent,it has high specific heat capacityHigh surface tension, andStable boiling and freezing points.The stable temperature of water, that is the ability to have a constant boiling and freezing points, is as a result of the hydrogen bonds existing between the water molecules.
The hydrogen bonds gives water molecules ability to hold heat better than any other substance.
Learn more about water properties here:
https://brainly.com/question/18681949
Answer: High specific heat capacity
Explanation:
I took the test
What is the uses of seawater as a source of renewable energy?
Explanation:
Desalination of seawater is considered a renewable source of water, although reducing its dependence on fossil fuel energy is needed for it to be fully renewable.
In a polar molecule, the partial positive charge on one molecule is attracted toward the partial _____ charge on a nearby molecule.
Answer:
negative
Explanation:
Opposite charges attract. Therefore the partial positive charge will be attracted to the partial negative charge
A solution has a [H3O+] of 1 × 10−3 M. What is the [OH−] of the solution?
A. 11 M
B. 14 M
C. 1 × 10−14 M
D. 1 × 10−11 M
Answer:
D. 1x10⁻¹¹ M
Explanation:
For any given aqueous solution the following formula is true:
1x10⁻¹⁴ = [H₃O⁺] * [OH⁻]
1x10⁻¹⁴ is the ion-product constant of water, Kw.
We input the given value of [H₃O⁺]:
1x10⁻¹⁴ = 1x10⁻³ * [OH⁻]
And solve for [OH⁻]:
[OH⁻] = 1x10⁻¹¹ M
Thus the correct answer is option D. 1x10⁻¹¹ M.
Answer:
D. 1x10⁻¹¹ M
Explanation:
I took the test :)
another name for constant boiling mixture
Answer:
Azeotrope
Explanation:
An azeotrope is a liquid mixture that has a constant boiling point and whose vapor has the same composition as the liquid
Another name for constant boiling mixture.
[tex]\sf\purple{Azeotrope.}[/tex] ✅
An azeotrope or a constant boiling point mixture is a mixture that has the same composition in liquid and vapour phase.[tex]\large\mathfrak{{\pmb{\underline{\orange{Happy\:learning }}{\orange{!}}}}}[/tex]
How many grams are in 2.000 moles of Cl2
Answer:
141.8g
Explanation:
because n(cl)=m(cl)/M(cl)
. A circuit is set up with two parallel resistors, each of a resistance of 250Ω. a. What is the total resistance for this circuit?
Answer:
125 ohms
Explanation:
since they're parallel we do
1/total resistance = (1/250 ohms) + (1/250 ohms)
then you get 2/250 ohms
then you flip it so it's equal to total resistance/1
250÷2= 125
2 NaOH + H2SO4 2 H2O + Na2S04
a. How many grams of sodium sulfate will be formed if you start with 300 grams of sodium
hydroxide?
Answer:
532.5 grams
Explanation:
The balanced chemical equation of this reaction is as follows:
2NaOH + H2SO4 → 2H2O + Na2S04
From the above balanced equation, it shows that 2 moles of sodium hydroxide (NaOH) produces 1 mole of sodium sulfate (Na2SO4).
Using mole = mass/molar mass to convert mass to mole
Molar mass of NaOH = 23 + 1 + 16 = 40g/mol
mole = 300/40
mole = 7.5moles of NaOH
Since 2 moles of sodium hydroxide (NaOH) produces 1 mole of sodium sulfate (Na2SO4).
Then, 7.5 moles of NaOH will produce 7.5/2 = 3.75moles of Na2SO4.
mole = mass/molar mass
Molar mass of Na2SO4 = 23(2) + 32 + 16(4)
= 46 + 32 + 64
= 142g/mol
Mass of Na2SO4 = 3.75 × 142
= 532.5g
what do u mean by change in state of matter?define it.
Answer:
The mode of changing from one state of matter into another state and back to the former or original state is called change in state of matter .
hope it is helpful to you
Answer:
change in one state from another and back in its own original is known as change in state of matter
explain observation Made when anhydrous calcium chloride and anhydrous copper 2 sulphate are separately exposed to the atmosphere for much 2 days
Aqueous sulfurous acid decomposes into sulfur dioxide gas and liquid water. Write a chemical equation for this reaction.
Answer:When trying to concentrate the solution by evaporation to produce waterless sulfurous acid it will decompose
Explanation:
Explanation:
here's the answer to your question
Which explains why the laws
motion are scientific laws?
O A. The theories of motion became laws after there was enough
evidence to prove they were true.
O B. The laws cannot be tested by experiments, but scientists know
that they are correct because they make sense mathematically.
c. The laws explain how objects move and are supported by
experimental evidence.
O D. The laws describe a wide range of observations of motion and can
be used to predict the motion of objects.
Did
Answer:
D
Explanation:
Scientific laws describe how things work with little to no exception. They do NOT provide an explanation to WHY something occurs.
Answer:
The answer is D because scientific laws describe how things work not why they happen.
Additional Activities
Direction: Sharpen your understanding in projectile motion. Calculate the maximum height reached and the horizontal range of the given launched angles and initial velocity of a projectile. You may opt to use the Projectile Motion Simulation with Air Friction by AERDEMIR which can be downloaded via Play Store for free.
1. To use the simulator, set the given values as shown in the left.
Start Angle = Launched Angle = refer to the table Start Velocity = Initial Velocity = 20 m/s
Change the gravitational acceleration to 9.8 only Delete the values in Air Density and Drag Coefficient
2. Deactivate the friction force by tapping the icon indicated in the above image.
The maximum height of an object, given the initial launch angle and initial velocity is found with:
h = v2 is in2θi 2g
h = v i 2 sin 2 θ i 2 g.