Answer:
D. they're close to filling their outer shell, fulfilling the octet rule
Explanation:
:)
What types of substances are considered drugs?
Answer:
Marijuana
Opiates
Opioids
Explanation:
_________ is a jellylike substance within cells.
Answer:
Cytoplasm
Explanation:
Cytoplasm is a jellylike substance within cells.
Answer: he is right
Explanation:
A chemist prepares a solution of iron(III) bromide (FeBr3) by measuring out 41.1 mg of FeBr3 into a 50. mL volumetric flask and filling to the mark with
distilled water.
Calculate the molarity of Br- anions in the chemist's solution
Be sure your answer is rounded to 2 significant digits.
Answer: The molarity of [tex]Br^-[/tex] anions in the chemist's solution is 0.0084 M
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.
[tex]Molarity=\frac{n\times 1000}{V_s}[/tex]
where,
n = moles of solute
[tex]V_s[/tex] = volume of solution in ml
moles of [tex]FeBr_3[/tex] = [tex]\frac{\text {given mass}}{\text {Molar mass}}=\frac{0.0411g}{295.6g/mol}=0.00014mol[/tex]
Now put all the given values in the formula of molality, we get
[tex]Molarity=\frac{0.00014\times 1000}{50}=0.0028[/tex]
As 1 mole of [tex]FeBr_3[/tex] gives = 3 moles of [tex]Br^-[/tex]
0.0028 moles of [tex]FeBr_3[/tex] gives = [tex]\frac{3}{1}\times 0.0028=0.0084 moles[/tex] of [tex]Br^-[/tex]
Thus the molarity of [tex]Br^-[/tex] anions in the chemist's solution is 0.0084 M
4) A 4.00 L balloon is filled with 0.297 moles of helium gas with a pressure
of 0.910 atm. Calculate the temperature, in Kelvin, of the gas. (KEEP 3 SIG
FIGS; DO NOT TYPE ANY UNITS)*
Answer: 149
Explanation:
Using the ideal gas equation; PV = nRT
P= Pressure = 0.910 atm, T= Temperature = ?
V= Volume = 4.0L R = Gas constant = 0.08206 L.atm/mol/K
n = number of moles = 0.297
Making 'T' the subject of the formular, we have;
T = P V/ n R = 0.910 x 4 / 0.297 x 0.08206
= 149
What determines the average kinetic energy of the particles in a gas?
A.
the number of collisions
B.
the number of particles
OC.
the size of the particles
D.
the temperature
Answer:
D
The temperature.
Explanation:
A student decreases the temperature of a 417 cm³ balloon from 278 K to 231 K. Assuming constant pressure, what should the new volume of the balloon be?
376 cm³
417 cm³
462 cm³
924 cm³
Answer:
346.5 cm³ or 347cm³
Explanation:
v1/T1 = v2/T2
417/278 = v2/231
v2 = 346.5 cm³
.
Showing a correct numerical setup, determine the percent composition by mass of carbon in baking soda (gram-formula mass - 84 grams per mole).
Answer:
Percentage Mass carbon = 14.3%
Explanation:
Baking soda which is sodium hydrogen bicarbonate has the molecular fomula, NaHCO3.
Atomic masses of each of the component atoms is, Na = 23; H = 1; C = 12; O = 16
Step 1: Molar mass of NaHCO3 = 23 + 1 + 12 + 3*16 = 84 g/mol
Step 2: Percentage mass of Carbon = (atomic mass of Carbon / molar mass of NaHCO3) * 100%
= (12 / 84) *100%
Percentage Mass of carbon = 14.3%
Please help me out on this question!!
Answer:
Water H2O
Explanation:
A solvent is defined as being able to dissolve other substances, the fertilizer is being dissolved in the water prior to watering the plants, therefore the water is the solvent in this case.
Pls help I’m dying plssssssdsssss
Answer:
number 3
Explanation:
1.
A car tire was inflated to 75 kPa at the repair shop where the
temperature is 15 °C. What is the pressure of the tire on the trip home
if the temperature of the road surface is 32 °C? (Write your answer
nearest whole number)
kPa
Answer:
THE PRESSURE OF THE TIRE ON THE TRIP HOME AT THE ROAD SURFACE TEMPERATURE OF 32°C IS 160 kPa.
Explanation:
Initial Pressure = 75 kPa
Initial temperature = 15 °C
Final temperature = 32 °C
Final pressure = unknown
Using the combined equation of gases;
P1V1/T1 = P2V2/ T2
Since the tire will have the same volume of air in it showing that volume of constant both at the repair shop and on the road surface.
The relationship between pressure and temperature is used with constant volume.
P1/T1 = P2/ T2
75 kPa / 15 °C = P2 / 32 °C
P2 = 75 kPa * 32 °C / 15 °C
P2 = 2400 kPa °C / 15 °C
P2 = 160 kPa.
So therefore, the pressure of the tire on the trip home when the temperature of the road surface is 32°C is 160 kPa.
2
3
4
5
6
What did Virchow observe that led him to determine one of the main components of cell theory?
Answer:
In the year 1850, Rudolf Virchow was studying cells under a microscope, when he observed that cells were dividing and forming new cells. Realizing what he had observed, he understood that living cells reproduce new cells through division
What is the oxidation number of Si
Answer:
0
Explanation:
Rice has a bulk density of 0.9 g/mL, but an individual grain of rice has a
density of 1.1 g/mL. Water has a density of 1.0 g/mL. What would happen to
a cup of rice when poured into a pot of water?
Answer:
Individual grain of rice will sink.
Explanation:
Given:
Rice bulk density = 0.9 g/ml,
Individual grain of rice density = 1.1 g/ml
Water density = 1.0 g/ml
Find:
What happens with a cup of rice when poured into water =?
Explanation:
Each piece of grains of rice will sink into the water because individual grains of rice has a higher density than water.
mixture of 75 cm3of oxygen and 12.5 cm3 of a gaseous hydrocarbon H were exploded in an eudiometer. After cooling to room temperature, 50 cm3 of gas was left and when this was shaken with KOH solution, 12.5 cm3 of oxygen remained. Given that all the volumes were measured at same temperature and pressure, calculate the molar mass of the hydrocarbon H.
Answer:
molar mass of C₃H ₈ = 44 g/mole
Explanation:
Computation of the amount of oxygen that reacts .
⇒ 75 - 12.5
⇒ 62.5 cm³
Computation of proportion of hydrocarbons
2 mole hydrocarbons 3n+1 oxygen
⇒ 3 n + 1 = [62.5 × 2] / 12.5
⇒ 3 n + 1 = 10
⇒ n = 3
So,
Formula of the hydrocarbon is C₃H ₈
Computation of molar mass of C₃H ₈
⇒ [12×3] + [1×8]
⇒ 44 g/mole
Please I need this answer quick I will give brainliest
A student decreases the temperature of a 417 cm³ balloon from 278 K to 231 K.
Assuming constant pressure, what should the new volume of the balloon be?
376 cm³
417 cm³
462 cm³
924 cm³
Answer:
The new volume of the balloon is [tex]346.5\ cm^3[/tex].
Explanation:
Initial volume of a balloon is 417 cm³
The temperature decreases from 278 K to 231 K.
It is required to find the new volume of the balloon if the pressure is constant pressure. At constant pressure, volume is directly proportional to the temperature. So,
[tex]V\propto T[/tex]
i.e.
[tex]\dfrac{V_1}{V_2}=\dfrac{T_1}{T_2}[/tex]
V₂ is final volume.
[tex]V_2=\dfrac{V_1T_2}{T_1}\\\\V_2=\dfrac{417\times 231}{278}\\\\V_2=346.5\ cm^3[/tex]
So, the new volume of the balloon is [tex]346.5\ cm^3[/tex].
How are electrons and positrons the same, and how are they different?
Answer:
A positron is the antimatter counterpart of an electron (also called anti-electron). ... The spin, a type of angular momentum carried by the electron and positron, is the same for both. However, the electron and positron have the opposite charge. The electron has a negative charge, and the positron has positive charge.
20. Which of the following is NOT true for the atoms 13N, 14N, and 'N?
a. They all have the same mass number.
b. They are isotopes.
c. They all have the same atomic number.
d. They all have 7 protons.
e. They all have 7 electrons.
Answer:
a ,e
Explanation:
math
They all have the same mass number
For the reaction NH4Cl (s)→NH3 (g) + HCl (g) at 25°C, ΔH = 176 kJ/moland ΔS = 0.285 kJ/(mol - K).
What is the ΔG, and will this reaction be spontaneous in the forward direction?
169 kJ/mol; no
-91 kJ/mol; yes
91 kJ/mol; no
91 kJ/mol; yes
Answer:
C: 91 kJ/mol; no
Explanation:
Just took the quiz! :)
The ΔG is 91kJ/mol and the reaction is not spontaneous in the forward direction and the correct option is option 3.
What is Gibbs free energy change?Gibbs free energy, also known as the Gibbs function, Gibbs energy, or free enthalpy, is a quantity that is used to measure the maximum amount of work done in a thermodynamic system when the temperature and pressure are kept constant.
The Gibbs free energy of the system is a state function because it is defined in terms of thermodynamic properties that are state functions.
The change in the Gibbs free energy of the system that occurs during a reaction is therefore equal to the change in the enthalpy of the system minus the change in the product of the temperature times the entropy of the system.
ΔG = ΔH - TΔS
Given,
ΔH = 176kJ/mol
ΔS = 0.285kJ/mol K
T = 25⁰C = 273 + 25 = 298K
ΔG = ΔH - TΔS
ΔG = 176000 - 298 × 285
= 91070 = 91 kJ/mol
Since ΔG is positive, the reaction is not spontaneous in the forward direction.
Therefore, the ΔG is 91kJ/mol and the reaction is not spontaneous in the forward direction and the correct option is option 3.
Learn more about Gibbs free energy change, here:
https://brainly.com/question/4002787
#SPJ3
Neutralization Reactions
PREDICT THE PRODUCTS OF THE FOLLOWING REACTIONS
+
HNO3+ Ba(OH)2
+
H3PO4 + Ca(OH)2
→
Answer:
2HNO3+ Ba(OH)2 = Ba(NO3)2 + 2H2O
H3PO4 + Ca(OH)2 = Ca3(PO4)2 + 6H2O
Explanation:
2HNO3+ Ba(OH)2 = Ba(NO3)2 + 2H2O
H3PO4 + Ca(OH)2 = Ca3(PO4)2 + 6H2O
H+
O2-
OH-
Ba2+
Ca2+
NO3-
P 5+, 3+, 3-
H2O
explain how redox reactions are the source of electron flow in batteries. how can a dead battery be said to have attained equilibrium?
Answer:
can u help me whith one of my qutions
Explanation:
if the freezing point of a substance is 68°C, what is its melting point?
The melting point of the substance has been [tex]\rm 68^\circ C[/tex].
The freezing point has been defined as the temperature above to which the substance exists in the liquid state, while below which the substance exist in the solid state.
Freezing point and melting pointThe melting point has been the temperature at which the solid starts to convert into the liquid state. The melting point and freezing point for the substances has been the same temperature.
Thus, the melting point of the substance whose freezing point has been [tex]\rm 68^\circ C[/tex] has been [tex]\rm 68^\circ C[/tex].
Learn more about freezing point, here:
https://brainly.com/question/2292439
The topmost layer of the Earth is made up of large pieces that fit together like a puzzle. However, these pieces don't stay still, and sometimes they rub against each other. When these large sections of the Earth’s crust, called tectonic plates, hit each other, they send vibrations through the surface of the Earth. These vibrations are seismic waves. Seismic waves are just like the ripples in a pond. But instead of traveling through water, they travel through the Earth. When they reach the Earth's surface, they make the ground shake. That's an earthquake.
Earthquakes are the result of?
A ripples traveling through water.
B Earth’s topmost layer sinking.
C vibrations from seismic waves.
D tectonic plates staying still.
Answer:
C- vibrations from seismic waves
Answer:
C vibrations from seismic waves.
Explanation:
The shifting rock in an earthquake causes vibrations called seismic waves.
What is one way in which chemistry affects your everyday life?
A. Refrigerators use energy more efficiently than they did 10 years
ago.
B. Tap water is safe to drink because it is monitored for harmful
substances.
c. Weather forecasts are now more accurate because of radar.
D. Watches are now more accurate because they are digitalized.
Answer: B
Explanation: Water is filtered with a bunch of chemicals which makes it drinkable.
9. What is the difference between physical weathering and chemical weathering?
Answer: Physical Weathering physically breaks the rock, while Chemical Weathering chemically changes the rock causing it to break.
Explanation: Physical Weathering happens naturally causing the rock to break. An example is roots growing into the concrete causing it to crack. Chemical Weathering on the other hand chemically changes the rock by a chemical reaction. An example is acid rain. Gas or other pollution mixing in with water causing acid rain.
hope this helps ;)
Which ion below is present in greatest concentration in a basic (alkaline) solution
Answer:
hydroxide ion / OH-
Explanation:
Basic solutions have a greater concentration of hydroxide ions than hydrogen (H+) ions
Q24. List all of the ways you can force the reaction to shift to the product 5 points
side. (There are 5 ways total)
Answer:
1) Increase temperature
2) Decrease temperature
3) Increase concentration of reactants
4) Increase pressure
5) Decrease pressure
Explanation:
Le Chatelier's Principle Fundamentals states that a chemical reaction at equilibrium that undergoes changes to pressure, temperature, or concentration, this will cause the equilibrium to shift in the opposite direction to offset the change.
1) Increase temperature
2) Decrease temperature
3) Increase concentration of reactants
4) Increase pressure
5) Decrease pressure
15. What is the name of Fl-?
A)Fluorous ion
B)Fluorine
C)Fluoride ion
D)Fluorine ion
Answer:
C: Flouride Ion
what happens to the grass molecules when it is eaten by the zebra?
Answer:
read below
Explanation:
When the zebra eats grass, it gets energy from the sun that has been stored in the grass. Similarly, the lion obtains energy stored in the zebra. The zebra and lion both obtain the sun's energy indirectly from the energy that the grass obtained through photosynthesis.
Answer/Explanation:
It gets energy from the sun that was inside of the grass.
It happens like this:
Sun gives energy to grass, grass gives energy to zebra.
Sun ---> Grass ---> Zebra
How many hours will it take for only 1.5625 mg to remain
Answer:
36 hours
Explanation:
Notice that you are given the actual table of how the isotope reduces , and it shows that for each period of 6 hours the isotope decays to half of the initial number.
EVery 6 hours, the reduction in number of mg of the isotope goes down in half'
100 mg, then 50 mg, then 25 mg, then 12.5 mg, then 6.25 mg, then 3.125 mg and finally (reaching 1.5625 mg
That was 6 periods of 6 hours each, which totals: 6 time 6 hours = 36 hours
What is the mass of two moles of HNO3?
Answer:
126 grams
Explanation:
What is the mass of two moles of HNO3?
H = 1g/mole = 1+
N = 14g/mole = 3-
O = 16g/mole = 2-
HNO3 = 63g/mole